A Look At Traffic - Transportation in the World

Job Searching: List of Transportation Engineering Companies

2012-01-18T20:01:00.000-08:00

I have been meaning to post this list of Transportation Engineering companies up for some time now. I created this list when I was job searching for a transportation engineering related job. I had a few more columns added to keep track of if I applied or not or what contact information I had with the company. While this list is by no means complete, I think it is a good starting point to start applying to some companies. It is a little "bike friendly bias" as well, sorry about that. I can only hope the links still work for you (if not, let me know). The locations are by no means complete, they just scattered information if I happened to look up where their offices are. Good luck in the job search!

List of Trans Inc


.	Company	Website	Locations of Offices (incomplete)
.	Alta Bicycle Share	http://www.altabicycleshare.com/careers/	Oregon
.	Bixi Bike Sharing	https://toronto.bixi.com/contact
.	SRF Consulting Group	http://www.srfconsulting.com/careers/Openings.aspx
.	Cambridge Systematics	http://www.camsys.com/com_career_opportunities.htm#tdf000246	NYC
.	Kittelson and Associates Inc.	http://www.kittelson.com/careers/opportunities/
.	The Mobility Group	http://www.mobilitygrp.com/employte1.htm	Irvine
.	Atkins	http://jobs.northamerica.atkinsglobal.com/tampa/transportation-design/jobid1273043-transportation-engineer-jobs	Tampa, Austin
.	STV	https://www4.ultirecruit.com/STV1000/JobBoard/ListJobs.aspx?__VT=ExtCan	Baltamore, Fairfax
.	SIMCO Engineering	http://www.simcopc.com/about.htm	NY
.	MTC	http://jobs.mtc.ca.gov/	Oakland
.	Fehr & Peers	http://www.fehrandpeers.com/career-opportunities/
.	IBI	http://www.ibigroup.com/Pages/Discipline.aspx?DisciplineId=3&CallType=Services	Irvine
.	URS	https://www.urs.apply2jobs.com/ProfExt/index.cfm?fuseaction=mExternal.returnToResults&CurrentPage=1
.	RSG	http://www.rsginc.com/transportation/	Vermont
.	Stantec	http://www.stantec.com/careers.html
.	HNTB	http://www.hntb.com/careers/job-search	Raleigh, Atlanta, Tampa
.	CH2MHill	http://www.careers.ch2m.com/worldwide/en/jobs-in/#my_careerlevel	World Wide
.	Dowling Associates	http://www.dowlinginc.com/	Oakland, CA
.	Parsons Brinckerhoff	http://search0.smartsearchonline.com/pb/jobs/process_jobsearch.asp	World Wide
.	Lee Engineering	http://www.leeengineering.com/Careers.html	Pheonix, TX, NM
.	Iteris	http://iteris.catsone.com/careers/	Richmond, VA
.	Advantec Consulting Engineers	http://www.advantec-usa.com/index.php?option=com_jobline&Itemid=96
.	Urban Crossroads	http://www.urbanxroads.com/careers.aspx
.	Wiley Engineering	http://www.wileyengineering.com/html/careers.html	NY
.	Halcrow	http://www.halcrow.com/Working-for-us/North-America-careers/
.	Parsons	http://www.parsons.com/careers/jobs/Pages/default.aspx	US
.	MINAGAR & ASSOCIATES, INC.	http://www.minagarinc.com/site_map.htm	Irvine
.	Hirsch/Green Transportation Consulting	http://www.hgtraffic.com/job_openings	LA
.	SSE	http://www.samschwartz.com/Careers/JobOpenings.aspx	NY
.	DKS	http://www.dksassociates.com/dks_careers.asp	Irvine, Dallas, Oaklan
.	Moffatt & Nichol	http://tbe.taleo.net/NA8/ats/careers/jobSearch.jsp?org=MOFFATTNICHOL&cws=1
.	KLD	http://www.kldcompanies.com/kld_employment.php
.	LLG	http://www.llgengineers.com/Pages/Careers/JobOpps.html	SD, Costa Mesa, Pasadena
.	Tran Systems	http://www.transystems.com/Home/Careers/Opportunities.aspx	Southern California, Midwest
.	ICF international	http://www.icfi.com/Markets/Transportation/
.	Willdan	http://www.willdan.com/careers.aspx
.	ATEC	http://www.atectrans.com/contact_us.html	Miami, Florida
.	VRPA	http://www.vrpatechnologies.com/qualifications.php
.	KOA	http://www.koacorporation.com/careers_openpositions.html	Southern California
.	IEM	http://www.iem.com/markets/transportation
.	ARUP	http://www.arup.com/Careers.aspx
.	Tindale and Oliver	http://www.tindaleoliver.com/e6.html
.	SMG	http://www.sysmetgroup.com/
.	DRMP Inc	http://www.drmp.com/Job_Listings.html
.	VA Consulting	http://www.vaconsultinginc.com/careers/jobs.html
.	FRA	http://www.fr-aleman.com/openings/openings.htm
.	T.Y. Lin	https://www7.ultirecruit.com/TYL1001/JobBoard/listjobs.aspx?Page=List	San Diego, Pasadena
.	LSA	http://www.lsa-assoc.com/employment.htm
.	FAA	http://www.faa.gov/jobs/
.	Jacobs	http://www.jacobs.com/careers.aspx?id=4454
.	FHWA	http://jobsearch.dot.gov/jobsearch.asp?jbf574=TD04&q=&jbf522=&salmin=&salmax=&paygrademin=&paygrademax=&jbf565=0&tm=&sort=rv&vw=d&brd=3876&ss=0&FedEmp=Y&FedPub=N&SUBMIT1.x=93&SUBMIT1.y=17
.	Hill Engineers	http://www.hillengineers.com/more/careers.html
.	Delta Engineers	http://www.deltaengineers.com/Careers.html
.	Mark Thomas & Company	http://www.markthomas.com/careers/
.	BLA	http://www.blainc.com/
.	CLR Analytics	http://clranalytics.com/	Irvine

Highway Traffic Congestion Solved: Queuing Lot’s

2011-12-06T18:19:00.001-08:00

Traffic jam’s are a common occurrence in California (among other states), where vehicles are plenty and roadways are never wide enough. Slowly but surely we are seeing parking lots creep into our highways. There has to come a point where eventually something must change. While we may not know what that “something” is, I want to outline a possible idea that could help reduce highway congestion, frustration, and save money/gas/emissions for drivers.

Traffic Congestion - Highways turning into Parking Lots

Before I dive into the explanation about this Queuing Lot idea, I need to outline some basics of a highway operational facility. A typical one lane highway road, can efficiently provide uncongested service for about 1,800 vehicles per hour. (some say 1,500, and others say 2,200, but we’ll stick with 1,800). Using loop detector data collected from the highways, we can see that this approximation holds by looking at a Performance graph of two highway measurements.

Flow v.s. Occupancy Curve - Classic shape of vehicles becoming congested on highway. Green line - Free Flow, Red - Maximum Capacity of Roadway - Slowing speeds, Yellow - Highway Breakdown

On the Vertical y-axis we see Flow (veh/5 min) and on the horizontal x-axis, we see Occupancy (%). Occupancy can easilstly thought of as “density” or how closely spaced the vehicles are. A Occupancy of 1.0 (ie. 100%) would be where all the vehicles on the road completely stopped like a parking lot taking up every inch of the pavement.

Before we move on, it’s important to look at the shape of this flow-occupancy curve. From just looking at it, we can see that the number of vehicles increases as occupancy/”density” increases almost in a linear fashion [Green Line], until it reaches a certain value. We start to see a maximum flow [Red Line] occur and then a tapper-off effect and a decrease in the flow of vehicles as occupancy continues to increase [Yellow Arrow]. From this we can assume there is a maximum peek value that has an efficient use of vehicles traveling on the roadway segment. Ideally, to keep traffic flowing and having the highways transporting the maximum number of vehicles possible, we want to restrict the number of vehicles on the roadway segment to a specific value. For this highway segment it turns out the capacity is 1,800 vehicles per hour per lane.

For a highway segment that is only connected to on and off ramps with metered controls. Highway ramp meters have been shown to be more effective then ineffective (Study 1, Study 2, Study 3).Typically ramp meters delay vehicles entering the highway for a few seconds to keep the highway from overcrowding, while also not letting the on-ramp build up to the arterial streets with vehicles. Ideally each vehicle would wait their full marginal delay time before entering the freeway. This is where Queuing Lots come into play.

Waiting lots at airports or other transportation hubs, sometime’s called kiss-and-ride lots, are a common effective solution for vehicles waiting to pick up their passenger(s). The idea behind Queuing Lots ©, is similar, allowing the driver to relax and wait, while keeping vehicle traffic on the highway operating at the maximum throughput possible. One way this could work, is when the highway is near peek capacity [Red Line], drivers entering the on-ramp would be diverted to a Queuing Lot, where they are assigned a designated amount of time to wait, until they can enter the highway. Depending on the amount of traffic, point of entry, point of exit, etc. a wait could be a few minutes or 20(+) minutes. In the Queuing Lot, drivers are free to turn off their car and make phone calls, listen to the radio, text message, shave, dance, etc. Once your time is up, your free to merge on the free-flowing highway.

Modeling this type of traffic behavior would be the most cost effective way to determine if this would reduce travel times overall. A real time monitoring and performance evaluation system would need to be continually adjusting for the optimum wait time for drivers. As for the emissions, frustration, gasoline and wear and tear savings they are straight forward.

The biggest downfall of Queuing Lots: Trying to get somewhere, when your parked in a actual parking lot.

405 Closure - Carmagedon in Southern California - 7/15 to 7/18, 2011

2011-07-14T23:06:00.000-07:00

This Weekend an epic closure of the 405 freeway in Southern California plans to shut down. This article attempts to revel the details of the closure to help in planning your movement/travels this weekend! So lets go over the Five W's to get an idea about what is going on!

Who: The I-405 Freeway
What: 10 mile section closed for 53 hours
Where: The 405 Freeway, from the 101 to Highway 10
When: 10 pm on Friday July, 15 2011 - 5 am on Monday July 18 2011
Why: As part of a $1 Billion dollar reconstruction project, which includes the instillation of a HOV lane and a sound wall as well as upgrading on and off ramps to the freeway.

Some Pictures taken on Friday (7/15/2011) afternoon of the area are included here to show the equipment and future project areas. The first two is of Wilshire Blvd overpass over the 405 and the other picture is near Mulholland Drive.

A map of the 10 mile segment can be seen below.

Section closed for Carmagedon

It has been mentioned that, "if you think you think you're going to bypass the closure by some secret canyon route, you and a million other people have the same idea," said Andrew Neiman a L.A. police Lt. Some PR advocates of the closure have gone so far as to make T-shirts of the event, almost to a point of mockery.

While most articles are predicting [1, 2, 3] major delays, some say that the warnings may be so successful that traffic will be light as they were during the 1984 Summer Olympics. Well just have to wait and see how this all turns out, hopefully drivers plan accordingly and arrive at their destination safely.

Bike Survey Analysis - Irvine California Bike Path Study

2011-04-20T20:42:00.000-07:00

Recently, a friend of mine and I had the chance to conduct a intercept survey on a nearby recreation path [map]. The Backbay bike/run/walk multi-purpose trail is about 20 miles and has connection to the mountain-to-the-sea trail in Irvine and Newport Beach. Being an avid biker myself, it interested me who was using this trail for bike riding. Our team headed out to the trail to pass out a slip of paper with a link to the survey on it. We had a pretty high success rate of bikers taking the slips of paper, but lower rates of people actually filling out the survey online. Most bikers seamed to be OK with accepting a slip of paper while riding by at 15-20mph.

We spent 4 hours total on two different days passing out the survey from 7-9am. Once on a Saturday, the other on a Thursday. This allowed us to capture a typical work day morning, as well as a recreational morning.
Sifting through the data, we have a variety of interesting results. I present a few charts and figures below to give a gist of what the data reveals. However I leave the free-response sections untouched, possibly to be talked about in a future blog post, or for the interested reader to inquire about.
Just looking at age and gender demographics from our survey sample size of 56 responses, we can see that a majority of riders are male and over the hill.

From this we can see that bike riding is really for all ages! Besides some of the basic demographic questions, our survey also asked about why people were bike riding on the path. We wanted to know if they were riding for recreation, commuting or training purposes. No surprise that this varied by day of week. Overall our survey collection (with a bias), found that a majority of riders were biking on the trail for commuting purposes on Thursday and mainly for recreation on Saturday.

If we then classify riders by commuters, trainers and recreation riders, we can compared how many miles they traveled (on the given day they filled out our survey). This could be interesting to see if their is much of a difference between the millage among these rider types.

Rider Type	Sample Size	Average Miles	Standard Deviation
Commuter	20	18.61	12.6
Recreation	30	31.51	22.25
Training	6	32.64	21.89

This table gives us an idea that trainers and recreation riders do travel further on their bike than commuters. Although relatively an obvious statement, interesting to see the average commuter travels almost 20 miles.

In addition to our survey, we were able to conduct bicycle counts on the trail as well. Through the use of proprietary technology, we were also able to generate count's on the trail for a 72 hour period. The results from these counts are show below.

Thursday: 622 Counts
Friday: 736 Counts
Saturday: 1,537 Counts

This tells us that that this path is heavily used on not only weekends, but also during the week. It is very exciting to know that all this bike riding is going on, even if alot of these counts are round trips.

In conclusion, we can see that bike's are commonly used for recreation and commuting on the back bay trail. We can also tell that this trail is heavily used, and should be continued to be maintained for cyclist to use. The survey produced alot more data then shown here in this post, but that will have to wait till next time!

Transportation by Feet

2011-03-08T17:56:00.000-08:00

How would you move through your city if you didn't have a car, bike or bus available?

When I imagine my life without a car or a bike or a bus, I look to walking to get around. While most people would begin to feel a little uneasy (not to mention fatigued), I propose it can be free and exhilarating way to live life to it's fullest. Life slows down when you walk and this slower pace of life can be more enjoyable as the minutes and hours pass more freely. It forces one to spend time and energy to get somewhere. Often riding my bike to places instead of driving is just as quick as if I had driven my car, so the alternate form of transportation is not an inconvenience in time. It's when the mode changes from driving or biking to walking that I am free to forget about timed schedules and constraints and just enjoy the outdoors. The walking trip is a positive addition to any activity, for example driving to the grocery is just a means to get to the store, but walking there is a stand alone activity that is an end to itself; it's just that powerful.

I am not sure what it is about walking that makes it an enjoyable activity, but people have taken it to the extreme and have walked across America, or from south to North [Pacific Crest Trail, Continental Divide, Appalachian Trail]. there must be something about "putting one foot in front of the other, don't look back, just keep on going" that is just so enjoyable.
Sometimes in our lives we are faced with situations where we don't have the "luxury" of having a car. For example, when traveling by plane, assuming we don't rent a car, we become dependent on public transportation and rely on our feet more to propel us. However when we are home, with our car so accessible, we use it. I have tried parking my car far away from my place of residence, or left a minimal amount of gas in the gas tank to limit my driving, but this only lasts for so long. It becomes more about changing my perspective of walking and planning my day accordingly.

What makes an area Walkable? What helps improve way finding? The Promenade in Santa Monica is pretty walkable, but still requires a drive and a parking space for visitors. The neighborhood of Woodbridge in Irvine is designed to be walkable, but has yet to be a prime example of "Walkable America". What if a city were given a rating on how walkable it was? Well, they have an app for that, as well as a website: http://www.walkscore.com/ where a score of 0-100 is given to a city based on a

patent-pending calculation. Which I believe is a "as the crow flies" distance to each of the amenities of a city. Amenities include things like, grocery stores, coffee shops, schools, parks, etc. etc. etc.

It turns out they are looking into a more sophisticated walk-ability algorithm. For example, using "intersections per square mile and average block length" they can better determine how walkable a place is, rather then "as a crow flies" distance to various locations. This is great stuff they are pursuing and excited where this will go! This more sophisticated calculation reminds me of an idea I had about intersections. I will share the idea here, hoping someone will steal it and actually implement it! The idea goes like this:

A wiki(a) for intersections in a city. Similar to how Wikipedia has a page for every topic in the world, this Wiki (crowd sourced, collaborative community) would have a page for every intersection in the country (or world). Allowing visitors to add to the existing intersection information or creating new pages for intersections that don't exist yet. Each page would be filled with a bit about theintersection, including (but not limited to),

Location of intersection (latitude, longitude and cross streets)
Pictures of the intersection
If the signal light's are timed or detected
If they have a pedestrian button and a bike button
How many crosswalks their are, and how much time they give you.
How long the yellow light is in each of the directions

Besides this general information, they would allow for the history of the intersection and previous accidents in the intersection, as well as a safety index for that intersection. Also users could mention future improvement options for this intersection. Giving a place for people to complain about the signal timing, or pedestrian safety (using 8-oh-my-stuck, of course).

Again just an idea...Some of the city's that are pretty walkable are here from the walkability site.

Although the walk score is a great promotional tool for real estate developers, it is also interesting to note that it could prevent people from attempting to walk more because their address has a low walkability score. This could help citizens rise up and argue for better walking amenities.

Mobile phone software developers have also developed apps for guided tours for different city's at: http://www.gpsmycity.com/ A good app idea indeed, however, a little on the pricey side for an app. However this could make for a great tour guide for a city. Although, a local tour guide might give you more information, while helping support the local community better. I had a similar idea to this, but more "wiki" based, again here are some initial details of the idea;

The idea is to Geo-tag people talking about their location at different places on the planet. Essentially a phone app, where it would record people talking and record a persons GPS location. This would allow people to see a map with overlays of different people talking about their surroundings. Similar to a guided tour at a museum, when they give you the audio tour. Except this would be the real world, and just random people mentioning what they are seeing. However, with a collaborative wiki online website, they would be able to mix other people's recording into one well done recording, of course keeping everything Creative Commons (ShareALike Licence). Just a thought.

Anyways, I feel that a walkable city can be more beneficial to citizens mental health and well being. After all there's no parking to worry about! It gives a great use of the often underused legs, and it's F R E E! So what is that secret component to making a city more walkable? Maybe it has little to do with the city's design, and more of people's perceptions of walking.

A Critique: The Capital Bikeshare Program in Washington D.C.

2011-02-08T10:46:00.000-08:00

Recently, I had a chance to give the Capital Bikeshare program a test ride while visiting Washington D.C. Overall, I was really impressed with the program, as it had done a lot of things right for such a bikeshare network to be successful. Rather than seaming 100% touristy, it felt like it was apart of the city, with regular commuters using it. So let's go into how the program works.

All through out the D.C. area there are currently 110 stations to rent bikes at. With over 1,000 bikes available, anyone with a credit card can go up to a kiosk and rent a bike. The bike can then be returned to the same location or a different Capital Bikeshare station. To rent the bike, simply swipe your credit card and click away on the kiosk, agreeing to a waiver and accepting the pricing terms. In a matter of a minute or two, your able to receive a 5 digit key code. You then can use this key code to unlock a bike of your choosing from the racks. Once unlocked, your free to roam about the city. However, the pricing scheme encourages short trips (less than 30 minutes).

The pricing of the bikeshare is designed to limit bikes from being used all day, and not allowing others to use them. For first time users, the bikeshare charges a $5 membership fee, for a 24 hour membership period. After this membership fee, the first 30 minutes are free. After the free 30 minutes are up, and the bike has not been returned to any of the station's a $1.50 fee is imposed on the credit card used to check out the bike. If the bike is still not returned within 90 minutes, then a $3.00 fee is charged. Each additional 30 minutes after is $6.00. Notice the different tiers of pricing to limit longer trips. This prevent's bikes being out for too long so others can use them. This also keeps trips just across town for a few errand's, rather than for tourist rental bike operation. This pricing scheme works well, as it keeps people on the bike moving to their destination, and responsible for returning the bike quickly. If a longer time was allowed, I feel that users would try to run in a grab a coffee while the bike wait's unattended outside the store. The program also allows for yearly memberships, which currently cost $75/year. This allows riders to have a personal "key" to unlock the bikes and by pass the credit card and kiosk hasstle. When considering initial bike investment, matinence fees, bike lock security and storage, the $75/year price tag is relatively attractable. It is worth mentioning that if the bike is not returned within 24 hours from being checked out, there is a $1000 charge for the bike.

Returning users, who have a 24 hour membership, simply use their credit card to obtain a new 5 digit code (using numbers 1,2 and 3) and rent a bike. I found this very handy, as long as you remeber which credit card you used. While visiting the city, I did happen to see a Capital Bikeshare vehicle with up to 4 bike racks on the back, so it could transport bikes to the different stations as necessary to make sure stations were not over or under supplied with bikes.

The bikes themselves, worked really well. They felt really solid to ride, and held up fine dropping of curb's and skidding in the snow. The tires were wide road slicks, with a high psi rating (65 psi+) to prevent punctures. The front bike rack is also a great addition to stow a backpack or some groceries. The bikes had a front Dynamo hub for a front light, and a kickstand for supporting the bike. The bike was also equipted with rear flasher lights, great for visability during night riding. The gearing was a simple 3 speed with an internal hub in the rear. The internal hub speeds gave good leverage for climbing the ascent's of the city, but had you spinning your gears on some of the downhills for not being able to go in a high enough gear. This is probably a good thing, to prevent people going too fast. One minor flaw is the internal hubs take a second or two to shift gears. This can be a little frustrating to try and shift quickly for a hill, but I guess it's better than the chain falling off and dealing with derailer problems. One of the nicest features of the bike, especially for a wet winter city like D.C. is the fenders and side protectors. This helped a lot from water splashing up your bike side while riding. While riding in light snow one morning, I was able to travel the 3 miles across town with only the bottom 6 inches of my dress pant's being wet. Not bad considering how wet it was outside.

Although the above mentioned seams like Capital Bikeshare is a perfectly implemented bikeshare program, it does have a few flaws worth mentioning.

1. 30 minutes is 30 minutes. No grace period. I found it a little annoying to be 2 minutes late returning a bike and having to pay $1.50. Not having any leeway to return the bike a minute or two late is a bit fustrating. Excpecially when trying to find a bikeshare rental kiosk rack, which leads me to the next flaw.

2. Once you leave the bike rental station, the only map of where the other bike stations are is at another bike station (or on your smart phone). I found this highly annoying, not remembering the directions to the next bike station while the 30 minute (free) clock is ticking down. A simple waterproof map built into the bike handle bars would be a huge improvement. I am unsure if it's intentional or not, but it seams like they want you to get lost, to be charged for additional time, or they encourage frequent users of the system, not tourists.

3. No helmet rentals. In a big city, where bike ride next to cars, a small helmet rental station would be greatly appreciated. Head wraps could be worn to protect others hair from being used in the same helmet. This simple addition, would be a added bonus to help make the city safer for cyclists.

Overall, it's a great program to have for a relatively flat city like D.C. A Bikeshare program may not be perfect for all citys, but a city like D.C. it works out really well. They seam to be even expanding it and looking for new locations for bike stations. It was a honor to participate in this cool bike program, and be able to see more of the city for pennies compared to a taxi or tour bus.

Riding around town in D.C. on the Capital Bikeshare Program for less than 30 minutes at a time: $5
Saving money on a taxi for a quick trip across town: $8 (+ emissions)
Flying off a curb on a rental bike and returning it without need to repair any damages: Priceless

Traffic Reporting Phone Number: 8-Oh-My-Stuck

2010-12-02T11:24:00.000-08:00

This post is to introduce a new service for people nationwide to help reduce stress from road rage. Whatever the cause of your driving frustration, this new phone number can be called 24/7 toll free to relive your anger. Before the details are laid out, here is the number to store in your phone:

8-Oh-My-Stuck OR (864)-697-8825

So, the next time your on the roadways and frustrated of the current congestion levels or other drivers, your free to call* and complain about your drive. Calls are recorded and limited to 3

minutes. Heres an Example Caller:

Be sure to mention the following three items:

1. Where are you? Approximate location, ie. What Highway/street you are on, what direction you are heading?

2. What appears to be the problem?

3. Frustrated? How mad are you?

This can be summed into an acronym. W.W.F. (Where? What? Frustrated?) to help you remember the issues to discuss. The whole idea of this is to eventually place the calls on a map to see where people are calling about and how bad the traffic is. Here's a prototype of the map that eventually could be implemented as this service grows!

With different phone calls coming into the service, and a rating system in place, I'm sure we can hear some exciting traffic reports from individuals in the field or even some humorous messages of individuals cursing out their current road frustration. So remember, just Call: 8-oh-my-stuck and talk about the W.W.F.

Also, texting "8-Oh-My-Stuck" is also available for those rapid fire thumbs! Standard Text messaging rates apply.**

*Hands free device required in CA, NY and others

** Texting while driving is illegal in some states

SR-73 - The Free Section of the Toll Road

2010-11-05T09:28:00.000-07:00

If you have ever driven on the 405 through sections of Orange County, CA you may have noticed their is the 73 toll road that parralls the 405. When I first heard of this, I always routed my trips away from it, even with google maps telling me to drive on it. It wasn't for a few months of living in Orange County that I finnaly learned, through word of mouth, that a section of the 73 was free to travel on. That's right a toll road that was free!! However, there was a minor catch, if you missed the last free exit, you would have to pay to exit the toll road past that.

So where is this free section of the 73 toll road? Heres a picture and a Map.

So although this link is small compared to the length of the entire 73, it is quite a useful link! Just remember that when heading south the last free exit is BISON AVE. There is a large sign that will let you know, but the exit is a small one lane exit, so be sure to be careful not to miss it.

When heading North on the 73, as long as you get on at Bison, or any street north of bison, your section on the 73 should be free. This free section of the 73 has come in handy for many UC Irvine students who commute to school from areas such as Costa Mesa and Newport Beach.

I am unsure why this link is provided for free to all commuters, but my guess is due to some deal with the city of Irvine or the University of California. As for the toll road making any money, here is a decent article.

Alternative Fuel Vehicles

2010-09-14T17:27:00.000-07:00

Over the past few months I have been thinking about the different types of vehicles that are arriving on the markets, and how it is changing the conventional Internal Combustion Engine (ICE) that uses Gasoline. Just within the past 10 years we have seen the expansive growth of Hybrid Vehicles, including cars like the Toyota Prius, and the Honda Insight. Within the last year we have seen the introduction of all battery electric vehicles, vehicles from TESLA Motors and the Nissan Leaf. We have also seen a cross between Hybrid vehicles and battery vehicles which is a plug in hybrid (PHEV). Additionally we have also seen an push from automakers like Ford, GM, Hyundai and others, to manufacture Hydrogen Vehicles.

While we do see many alternatives to Gasoline powered vehicles, we also see a push for gasoline powered vehicles to continue to remain in the market. Due to increased fuel efficiency in modern day cars we continually see a increased Miles per Gallon (MPG) in new cars. This push for higher MPG has even inspired a Automotive X-prize competition (know for it's Space X-Prize competition).

The Automotive X-Prize is designed to get engineers thinking outside the box in terms of fuel economy. The goal is to develop a "commercially viable" vehicle that will get at least 100 mpg. - AutoBlog.com

The winner of a Race will receive a 10 million dollar prize. As of today there is 7 vehicles left for the final race between all vehicles. Updates about the Progressive Automotive X-Prize can be found from their website: http://www.progressiveautoxprize.org/

In conclusion, even with these increased number of alternative fuel vehicles, we see a continued use of gasoline powered vehicles and a push for improved gasoline fuel efficiency. This advancement will continue to keep alternative fuel vehicles out of the main market share, as they have high barriers to entry as it is. It will be interesting to see what happens. If we don't see automakers offering 100 MPG, you can always do it your self.

Pedestrian Behavior at Crosswalks and Pedestrian-Motor Interactions - Written by David Kim

2010-04-13T16:11:00.001-07:00

Introduction

One aspect of traffic that is not usually thought of as part of congestion is pedestrians. Just as vehicles use the roads and the network system to travel, pedestrian are able to do the same sometimes causing more congestion or even accidents. Though, the amount of pedestrian injuries and death have decreased over the years, there is a clear sign that there are still a large number of pedestrian being injured each year (~100,000) and pedestrian deaths each year (~4700) in the United States¹. Pedestrian deaths alone make up of about 11 percent of all motor vehicle deaths².

While these accidents are undoubtedly uncommon, these statistics alone make it important to evaluate the factors which play into these injuries and deaths. One of the goals of transportation planning and engineering is to ensure safety to all those who use the system.

There are many factors which play a role in pedestrian/motor accidents. Such factors would include age of the pedestrians, pedestrian walking speeds, vehicle speeds, road width, and etc.

·
Age - Through different studies and observations, it is noted that the elderly and children are more prone to these accidents which involve pedestrian/motor incidents.

·
Pedestrian Speed - The Federal Highway Administration (FHWA) suggests pedestrian walking speed of 4 ft/sec be used in traffic signal timing³. At the same time it was noted by FHWA that a little less than one-third of pedestrians walk at or below 4 ft/sec⁴. However, this noted pedestrian walking speed would obviously depend on many factors such as age and location and so forth.

Case Study – Irvine, CA

Data was collected at Bridge Ave and Campus Dr. to evaluate the average speed of pedestrians, and also determine whether this 4 ft/sec standard for traffic signal timing was adequate for safe passage for pedestrians. Pedestrians were timed from the moment they stepped off the curb to the moment that step onto the curb of the opposite side of the roadway. The actual walking speed was calculated by using Google Earth and measuring the distance for each crosswalk, and using that distance to divide the time spent crossing the street. A total of 78 pedestrian were timed at the intersection from 12:45pm to 1:45pm. The signal timing was also accounted for at this intersection, and as a result it was noted that this particular intersection followed the suggested standard of 4 ft/sec.

(All Sample Data)	All Pedestrians	Single walking Pedestrians	Pedestrian in pairs	Males	Females
# in sample	78	63	15	34	30
MeanWalking Speed	4.6808	4.7735	4.2854	4.7216	4.8322
Variance	0.4658	0.4257	0.4322	.4726	.3944
Standard Deviation	0.6825	0.6525	0.6574	0.6875	0.6280

Table 1 – Data Collected from Bridge Ave. and Campus Dr. intersection

Once the data was collected a hypothesis test was performed on all 5 categories listed in table 1.

Figure 1 – Histogram of pedestrian speeds

Jaywalking

One factor that is looked into further was the possibility that males jaywalk more often than females would, and thereby assuming that there is a correlation between jaywalking and an increase in deaths. The method of determining if there is a correlation was to first take a survey on males and female preferences of jaywalking. The goal was to obtain at least 30 male responses and female responses. A simple survey containing 3 questions was distributed in to obtain data. The 3 questions included determining their sex, their rating on the danger of jaywalking (a rating from 1=safe to 10=dangerous), and how often they jaywalk per month. The survey was then distributed to a large group of friends. Most were college age students, but some adults. A total of 74 responses was collected that which included 39 responses from males and 35 from females.

Figures 2 & 3 – Histogram of Perceived Jaywalking Danger. Males on the left and females on the right

Figures 4 & 5 – Histograms of Jaywalking Frequency. Females on the left and Males on the right.

In conclusion from the data and results of the hypothesis testing it was shown that there is an obvious difference between males and females in terms of their perceived danger of jaywalking as well as the frequency as to which they jaywalk. Nevertheless, note must be taken to the fact that the sampling frame for the population which is desired is not to accurate, as the sampling frame consisted mainly of young adults of a particular group. Therefore, it is able to provide a grounded assumption in stating that males then do jaywalk more often than females, and males view jaywalking less dangerous than females do thereby possibly correlating with why 70% of pedestrian deaths are males.

Pedestrian Accident Prevention

In the end, the purpose of evaluating different pedestrian characteristics or behaviors is to be able to implement solutions pedestrian accidents. There are various methods being implemented to reduce the amount of accidents occurring with pedestrian/motor incidents. However, according to the National Highway Safety Traffic Administration (NHSTA), from the year 1998 to 2008 there has only been a 16% decrease in pedestrian deaths⁵, while there being no defined factor as to whether this decrease is due to prevention methods or not.

Figure 6 - Pedestrian Deaths from 1997 to 2008

First, it is necessary to identify different types of measures being taken. These methods can be separated into 4 sections: managing vehicle speeds, separating vehicles and pedestrians in time, separating vehicles and pedestrians in space, and increasing visibility and awareness for motorists⁶. Four methods from these groups will be looked upon in this paper and they include marked vs. unmarked crosswalks, and signs, advanced stop signs, and flashing amber lights.

· Signs, Advanced Stop Lines, and Flashing Amber Lights – This creates a greater awareness for motorist as they approach areas where pedestrians may be crossing. Studies have shown that signs, advanced stop lines, and flashing amber lights revealed that addition of signs and advanced stop lines increased motorist awareness which led to a lower amount of vehicular/pedestrian conflicts at the crosswalks⁷. The flashing amber lights did not significantly improve any pedestrian safety.
· Marked V.s. Unmarked Crosswalks - One method that has been used worldwide as a measure to “increase” safety in pedestrians is the use of marked crosswalks. The reason marked crosswalks have been used in the first place it to further provide safety in ensuring the pedestrian safe passage as they cross a street. Marked crosswalks have usually been placed in uncontrolled locations and midblock locations. One of the reasons why is to increase visibility and awareness of the motorist as they approach crosswalks, thereby prompting earlier slowing down of cars and so forth. However according to many papers and studies there has been an assumption made that marked crosswalks possibly give a false sense of security.

Conclusion

Pedestrian deaths and injuries due to vehicular/pedestrian collisions continue to occur even while measures are being taken. In reality, pedestrian deaths per year in the US have not declined much over the past 10 or more years. Factors and characteristics need to be analyzed continuously in order to fully determine what measures would be effective in being a solution to this problem at hand. From this study it has been noted that jaywalking may be a concern for males as males make up of 70% pedestrian deaths each year, and through a series of data collection, surveying, and analysis, it has been shown that males tend to view jaywalking less dangerous and jaywalk more than their opposing gender. Furthermore, an evaluation of the FHWA suggested speed of 4 ft/sec for traffic signal timing was performed. Results showed that this speed holds and accommodates most pedestrians. However, for both of these tests, proportional sampling was not exercised as the primary group found in both sampling frames consisted of college age students and young adults. Therefore, age groups such as the elderly and young children were underrepresented or not even represented at all. However, the tests performed and the data collected provides starting assumption/foundations for such analysis.

However, one of the largest problems encountered with the analysis of pedestrian accident prevention is the fact that it is a rare occurring event. Though data may be found on the subject in databases stored by NHTSA, the amount of accidents is so low and so disperse that it makes it difficult for the evaluation of different factors that may correlate with the occurrence of these accidents as well as the effectiveness of implemented methods. As a result only through further testing and studies, can this problem be minimized.

notes

¹Retting, Richard A. “A Review of Evidence-Based Traffic Engineering Measures Designed to Reduce Pedestrian-Motor Vehicle Crashes” American Journal of Public Health.Vol. 93, No. 9. 2003

²Retting, Richard A. “A Review of Evidence-Based Traffic Engineering Measures Designed to Reduce Pedestrian-Motor Vehicle Crashes” American Journal of Public Health.Vol. 93, No. 9. 2003

³Tarawneh, Mohammed S. “Evaluation of Pedestrian Speed in Jordan with Investigation of Some Contributing Factors”. Journal of Safety Research. Vol. 32. 2001, 229-236.

⁴Tarawneh, Mohammed S. “Evaluation of Pedestrian Speed in Jordan with Investigation of Some Contributing Factors”. Journal of Safety Research. Vol. 32. 2001, 229-236.

⁵NHTSA’s National Center for Statistics and Analysis. Traffic Safety Facts - 2008 Data – Pedestrians. www.nhtsa.gov

⁶Retting, Richard A. “A Review of Evidence-Based Traffic Engineering Measures Designed to Reduce Pedestrian-Motor Vehicle Crashes” American Journal of Public Health.Vol. 93, No. 9. 2003

⁷Houten, Ron Van. “The Influence of Signs Prompting Motorists to Yield Before Marked Crosswalks on Motor Vehicle-Pedestrian Conlficts at Crosswalks with Flashing Amber”. Accident Analysis and Prevention. Vol. 23, No. 3. 1992, 217-225.

3 Hours of Video - All about Traffic

2010-02-26T08:39:00.000-08:00

Today I wanna share with you two videos that talk about some of the truly interesting aspects of traffic. This first video is a round table discussion of professors who are all very well educated. They give a nice perspective from multiple disciplines which makes for an interesting round table. The video can be seen here:
http://www.youtube.com/watch?v=ux3BjI3WYs0 (1hr, 50 min)

The Second video is by the author of a book called Traffic: Why we drive the way we do ([1][2][3]). It is part of the Authors@google talks. He presents some fascinating features of traffic. His book follows along the same line of the talk, so if you can't get enough, I recommend checking out the book!

I hope these videos can begin to show the need for inter-diciplins to get together and work towards a solution.I belive a diverse group of individuals from all areas, is a step in the right direction to help deal with this traffic problem.

Inter-vehicle Communication

2010-02-22T12:33:00.001-08:00

In 1986, a group of transportation experts from academia and the public and private sector looked ahead by 5 years to 1991, when a new transportation bill was scheduled to be enacted, to develop what the future of transportation should look like¹. This became known as "Mobility 2000". Mobility 2000 proposed for a natural effort that helped set the foundation for future technological growth in transportation, they called it Intelligent Vehicle Highway System or IVHS for short. By 1990’s road transportation professionals began to recognize that electronic sensors and computational power were decreasing in price and could become highly applicable to traffic and vehicular management, thus a new field of study was discovered. This technological gold mine became known as Intelligent Transportation Systems². ITS, as defined by Joseph M. Sussman, “combines high technology and improvements in information systems, communication, sensors and advanced mathematical models with the conventional world of surface transportation infrastructure”³. Essentially ITS is taking advanced knowledge from mathematics and technology and implementing it into transportation to improve safety, reduce environmental impact of transportation and increase efficiency. The emergence of this new technology in an old field allows for increased efficiency for road conditions and enhanced safety to drivers and passengers alike.

ITS has now become a much broader term to describe many areas of technology being implemented on the roadways. Some of these technological ideas include; automatic road enforcement, collision avoidance systems, dynamic traffic light sequence, drive log recording, pedestrian awareness system, and Inter-Vehicle Communication, among many other flourishing ideas. In this section of the post I will focus primarily on Inter-vehicle communications. IVC allows for instant, automatic, wireless transfer of information between two or more vehicles on a roadway. With wireless communication and processing of live data on a road way, drivers can become aware of critical information before it's too late. The overall theory of IVC is essentially, taking data from each of the cars on the roadway, (ie. their position, location, speed, proximity to other cars, origin, # of miles driven on current trip, destination, etc.) and sending it to other IVC implemented cars. The majority of this data would be collected through a built in GPS device and on-board sensors. All this data can then be transmitted to nearby cars on the road and displayed to drivers to be informed about the road ahead.

⁴

To see the effectiveness of IVC let's look at an example of how this would all work. Imagine a car, let’s call it Auto1, driving along a slowly winding highway at the speed limit of 65mph. To Auto1 everything seams fine, with light traffic on the road, and minimal congestion to worry about. Normally, Auto1 would be fine and arrive at his/her destination on time. However, today there is an accident just up the road. This accident has caused major congestion on the highway segment that Auto1 is about to pass through. Due to the quickness of the accident occurring, the radio has not given any updates on the highway that Auto1 is on. However, because of the implementation of Inter-Vehicle Communication, cars at the location of the crash are able to transmit their speed. At the accident site, these speeds would be typically less than 10 mph, or possible even 0 mph. IVC is able to collect these real time speeds of the cars around the accident and process this information, using a computer algorithm, to conclude that there has been an accident or some other reason for slow down, on the highway. Using a multi-hop relay signal between the accident and Auto1, Auto1 can be notified of the accident and then re-route its path so it does not experience any traffic.
Now that an example of Inter-vehicle communication has been outlined and put into context of it applicability and safety I would like to write about the heart of the technology. IVC relies on multiple technological advancements and I will show how it all comes together. It allows for a whole new range of possibilities on the highway, but IVC also has its limitations.

The actual device for IVC would be about the size of a cell phone and installed somewhere within the dash of a car. It would operate on the 5.850-5.925 GHz frequency⁵. This range of frequency has been dedicated for use of IVC in America. The 5 GHz range allows for high bandwidth of data transfer on an uninterrupted channel. Current speeds of up to 6 Mega bits per second, but future developments would allow for 27 Mega bits per second⁶. However, unlike GPS and cell phone wireless signals, this Dedicated Short Range Communication (DSRC) link in the 5 GHz band only allows for communication within a 1000 meter radius. Furthermore, actual operating range is limited to a 200 meter radius, but this distance allows for sufficient communication on most roadways. Each device on a car will be able to broadcast a message, as well as receive multiple incoming messages from other vehicular broadcasts. Research in Europe on a project called CarTALK and Fleetnet have looked into the potential of ad hoc communication between vehicles. An Ad hoc network allows for communication between vehicles to connect and transmit signals on the fly without the need for a base station. Essentially this saves money on implementation costs and increases efficiency in communication between cars.

CarTALK researchers found that a multi-hop communication link between cars worked very well in sending information back upstream⁷. Multi-hop communication allows for a broad casted signal to be "grabbed" by cars upstream and rebroadcasted for cars further up stream to grab the signal and retransmit it. Implementation of multi-hop communication allows for information and warning signals to be alerted to drivers before they would be visually aware of the situation. Studies in Europe have shown that warning signals about the road ahead allows for early braking which resulted in crash reduction of 3.6%⁸. This multi-hop communication design will make roads safer for drivers and allow for low implementation costs making it economically feasible.
A major drawback to IVC is that it relies on a significant percentage of cars on the roadway, having the technology installed to be useful. Both for effective data transfer and amount of information to be relevant, about 2% of cars would need to have the technology implemented⁹. It is expected that IVC would have similar implementation characteristics to GPS. GPS stands for Global Positioning System and uses 24 orbiting satellites to find the exact location, within 3 meters, of a GPS device. GPS allows for speed, miles traveled, and routes to be determined on the fly. Although GPS has not been required by law, it has infiltrated about 7% of American vehicles through consumer demand¹⁰. GPS offers drivers an improved driving experience that allows drivers to calculate directions and view dynamic maps of city streets and highways. IVC expands these capabilities for drivers and allows for more advanced features of drivers that GPS alone wouldn’t be able to offer. Recently, we have seen Google introduce it's own GPS software on it's Android cell phone platform with Google Navigation. I belive it would also be possible for Google to develop an IVC type application for cars to communicate with one another almost automatically, similar to their implementation of croud souring for speeds on roadways. This would do away with alot of the barriers associated with IVC, like the base stations and the DSRC antenna. Essentially this would replace the proposed base station network and just use the exciting cell phone tower network. The possibilities of bringing IVC technology to the everyday user with a android supported cellphone would be phenomenal. A move by google to support this feature could really change the future of IVC.

Taking a step back and looking at Inter-Vehicle Communication, we see that is amazing technology that is being developed for future improvements in transportation. It is my personal belief that this technology has the capabilities to change travel as we know it today. In 2003, ITS America, an organization whose mission is to improve transportation through research, promotion and deployment, set a goal to have zero fatalities on roadways. With the design of IVC, I believe we are one step closer to that goal.

It is my belief that Intelligent Transportation Systems has the ability to change transportation as we know it today. Inter-Vehicle Communication has the potential to increase efficiency on the roadways and well as increase safety. I hope to see an adoption of change towards this technology.

notes

¹Sussman, Joseph M. Perspectives on intelligent transportation systems (ITS). New York: Springer, 2005. Pg. 4

²Bishop, Richard. Intelligent transportation systems library. Boston: Artech House, 2005. Pg. 2

³Sussman, Joseph M. Perspectives on intelligent transportation systems (ITS). New York: Springer, 2005. Pg 1

⁴http://www.ece.osu.edu/~ekici/images/v2i.jpg

⁵Bishop, Richard. Intelligent transportation systems library. Boston: Artech House, 2005. pg. 180

⁶Recker, Wilfred W.. "Instantaneous information propagation in a traffic stream." Transportation Research Part B: Methodological 40Mar 2006 230-250. Web.25 May 2009. <http://cat.inist.fr/?aModele=afficheN&cpsidt=17547219>.

⁷Bishop, Richard. Intelligent transportation systems library. Boston: Artech House, 2005. pg 188

⁸Bishop, Richard. Intelligent transportation systems library. Boston: Artech House, 2005. pg. 189

⁹Recker, Wilfred W.. "Instantaneous information propagation in a traffic stream." Transportation Research Part B: Methodological 40Mar 2006 230-250. Web.25 May 2009. <http://cat.inist.fr/?aModele=afficheN&cpsidt=17547219>.

¹⁰Fehrenbacher, Katie. "GPS Navigation: Nokia Looks to Cars." GigaOM. 30 Oct. 2006. 25 May 2009 <http://gigaom.com/>.

Variable Speed Limits: An Informative Piece

2010-01-24T18:14:00.001-08:00

I wanted to write a post on Variable Speed Limits or (VSL) because I feel that they can be used to effectively reduce traffic on freeways. So to start off;

What are Variable Speed Limits?

They are speed limit signs that can change. Instead of having a posted speed limit on a metal sign that never changes, VSL sign's are able to change to based on current road conditions either weather or traffic conditions.

Are they Effective?

VSL have been shown to not only reduce travel times in congested traffic¹ , but also to increase safety on the road ways².

Variable Speed Limits can be very useful for reducing congestion or implementing safer speed limits based on weather conditions. When traffic comes to a halt in one location on the freeway (due to an accident or just a general slow down) it's possible to have cars continually braking back upstream. The transition of these stopped cars to the braking cars can be considered to be a wave moving. Similar to how domino's fall, where the upright dominoes representing the moving cars, and the knocked over dominoes representing the stopped cars, there is a transition zone that moves along the freeway. The speed of this "wave" has been shown to travel as fast as 8-10 mph. The speed of the wave ultimately depends on the density of cars per mile. The density of cars can again be related to dominoes. The closer the dominoes are placed together, the wave of them being knocked down travels faster. If the dominoes are spaced further apart, the wave knocking them down travels slower³. Essentially, the dominoes has to fall for a smaller amount of time before it transfers it's energy to the next dominoes.
Similarly, spacing between cars has an effect on the backward traveling wave. A higher density of cars, or stated another way; cars close together, continue to have cars stop quickly for slowing cars. For cars that are more spaced out, a wave does not travel as quickly to cars upstream.
By adjusting the speed limit upstream of the slow down, can reduce the number of people entering the jam. This helps decrease density, which helps with dispersing the wave. Optimizing the upstream speed to just the right value can essentially dissolve the wave moving upstream. These changes in speed would remain until the traffic improves to free flow conditions.
There has been two main approaches to finding how to calculate the speed of the Variable speed limit signs. One approach is to try to make the local speed of the highway uniform. Basically, looking at an average of the speed way over a few miles ahead, and a few miles behind the current location. This aims to reach 1 overall speed limit that all cars ad hear to. This method however tends to reduce travel time, by imposing speed limits that are much lower than normal, and does not seam to improve safety. The second method tries to prevent the highway from becoming too congested and over populated. This method of reducing density has been shown to be more efficient⁴.
I really feel Variable Speed Limit signs are great, because they are dynamic to the current road conditions. Rather then having a static sign posting 65 mph, even when the highway does not support such speeds, it can help future traffic utilize the full capacity of the highway.⁵

So implementation of VSL seams like a good idea, but it not widely used, especially in the US. This is most likely due to two reasons, besides obvious money and time constraints.

Drivers need to know about VSL. They need to know that the speed of the freeway can change. This was alot of the motivation for this post.
Even if drivers do know how VSL works, they still must remember the new speed limit. Changing the speed limit of a freeway, normally to be found with a speed of 65 mph, can be a little difficult to become acclimated to, as well as remembering the new speed limit for the time being⁶.

Well I hope this clarifies what Variable Speed Limit's are and that you too become a proponent of using them!

Update: Implementation in Seattle and it's effects: http://www.howwedrive.com/2010/09/16/traffic-and-algorithms-in-seattle/

notes

¹P.Breton, A. Hegyi, B. De Schutter, and H. Hellendoorn, "Shock wave
elimination/reduction by optimal coordination of variable speed
limits," Proceedings of the IEEE 5th international conference on
intelligent Transportation Systems (ITSC'02), Singapore, pp. 225-230,
Sept. 2002

²Chris Lee, Bruce Hellinga, Frank Saccomanno, "Evaluation of Variable speed limits to improve traffic saftey", Transportation Research Part C 14 (2006) 213-228

³Falling Dominoes: Problem 71-19, by B. G. McLachlan, G. Beaupre, A. B. Cox and L. Gore SIAM Review © 1983 Society for Industrial and Applied Mathematics.

⁴P.Breton, A. Hegyi, B. De Schutter, and H. Hellendoorn, "Shock wave
elimination/reduction by optimal coordination of variable speed
limits," Proceedings of the IEEE 5th international conference on
intelligent Transportation Systems (ITSC'02), Singapore, pp. 225-230,
Sept. 2002

⁵As a side note: It can also be seen as cars are the thief of roadway, where each car try's to consume as much roadway as possible. Since most drivers are selfish, they try to consume every piece of roadway available. VSL put a limitation on this robbery, and restrict these cars from only consuming so much roadway per hour.

⁶Juha Luoma and Pirkko Rama, "Effects of variable speed limit signs on speed behavior and recall of signs", Traffic Engineering + Control pp. 234-237

Tri-proportional Method example problem

2009-10-31T16:57:00.000-07:00

Heres a link to the document for the Tri-proportional method problem.

http://docs.google.com/fileview?id=0B-HnV83xISMvY2MwMTg3M2UtYTE4Mi00MGY2LTlmZTUtNGM0Mzc5MTdiMDQx&hl=en

The Flux of LA Over the summers from 2003-2008

2009-05-30T18:22:00.000-07:00

In this case study, I wanted to look at the net flux of L.A. over the summer months. To do this I treated the Los Angeles Area as a "black box" thus only looking at the main highways going into and out of the LA area. For each year I took data using PEMS, It was taken between Memorial day and Labor day. The exact dates are Memorial Day and Labor day are listed here:

May 23rd, 2003 and September 1st, 2003

May 28th, 2004 and September 6th, 2004

May 27th, 2005 and September 5th, 2005

May 26th, 2006 and September 4th, 2006

May 25th, 2007 and September 3rd, 2007

May 23rd, 2008 and September 1st, 2008

Each of these consists of 101 days which allows for the tail end of the data to be a little off. Although this is not perfect, it does work out quite well for comparing July 4th traffic in the region for each of the years studied.

As a macroscopic study, the aterial streets or much smaller highways are essentially ignored. My choice on highways was generally chosen by looking at maps.google.com. The exact location was determined based on two things. 1) The location of the least amount of major highways pulling off the highway I was studying. Essentially looking for the "neck" of the bottle neck and 2) The amount of accurate data I could find from the PeMS data loop counters. I looked for a high observance percentage. However, I should note, that some summers only provided me with 0% observance ratio, thus giving data that is only a guess at best and leaves some of the charts lacking accurate data. The loop detectors on some highways were only recently installed, and data in the region was simply just unavailable. Here is a map of where the loop detectors I used are located. Notice they tried to surround the L.A. region as best as possible.

View Traffic Study - LA Flux over summer Loop Locations in a larger map

Once each location had been determined and data was collected for the inbound and outbound directions for the years 2003 - 2008, I was ready to calculate Net Flux!
Flux in this study will simply be defined as the the amount of cars that flows on a highway over the summer months. The Net flux is simply the difference between the amount of cars going into L.A. subtracted from the amount of cars leaving the L.A. area. I should note that this can be a positive or negative number. If their are more cars leaving the L.A. area, then we would have a negative number. On average, however we normally have more cars entering LA then leaving LA, leaving the net flux to be a positive number. Here we see the data for each of the years.

Key: Light Blue - 2003, Red - 2004, Orange - 2005, Green - 2006, Darker Blue - 2007, Purple - 2008. Note: the time scale in the graph shows it is 2003, However, this is only because there must be a year associated with these dates. Simply ignore the year 2003 scaling of the graph. This graph shows the Net volume of vehicles driving into the LA study area (positive values) or leaving the LA study area (negative values).

Data Analysis Conclusions

Now that we have collected all the data, and organized it in a coherent way so it can be displayed on a graph, we can begin to draw some conclusions about the L.A. area during the summers between 2003 and 2008. The first thing the data shows us is that we have higher traffic volumes in the years 2003,2004,2005 and 2006 then we do in 2007, and 2008. This maybe linked to higher gas prices during the 2007 and 2008 time period.
Also notice the traffic on the 4th of July. There is typically a decline around this time in each of the years. Possibly people are relaxing after lighting up the sky. Later in the month of July we see low volumes of traffic during the middle of the month. This could be the reason for choosing to close the 405 freeway for construction in 2011. Towards the end of our study period we see traffic volumes pick up quite a bit. Three day weekends sometimes start early with eager travelers looking for an extended vacation to leave the LA area.

405 Northbound - Monday V.s Friday Traffic Comparison

2009-05-07T21:24:00.000-07:00

Looking at the 405 Northbound Highway between Sand Canyon Ave and Jeffery Ave on Monday May 1st and Friday May 4th 2009, I found that this particular highway segment was interesting to look at, due to heavy traffic volumes in both the Am and Pm hours.
View Larger Map

Comparing the morning and evening times for Monday and Friday, we can draw some heavy conclusions about when people are leaving and getting on the road. The data has been collected from loop detectors on the highway, which I extracted using PEMS. I then looked at the Flow (vehicle/time) and speed(mph). The data is grouped into 5 minute intervals for the highest resolution avalable from PEMS. Before we look at the data plots, I would like to say that the more flow on the highway, resulting in more cars on the highway, which should reduce our speeds. Keep this in mind when looking at the graphs. The Flow was calculated as an average of all the lanes, thus giving one line in the graph, rather then four flow lines for four lanes. I left each of the lane speed data in there respective colors to give insight into the faster and slower lanes (More on this in another article).

Monday Flow and Lane Speeds

Key: Purple - Average Flow over all the lanes. Blue - Lane 1 (Inside lane next to divider). Red - Lane 2. Yellow - Lane 3. Green - Lane 4 ("trucking lane").

Friday Flow and Lane Speeds

Key: Purple - Average Flow over all the lanes. Blue - Lane 1 (Inside lane next to divider). Red - Lane 2. Yellow - Lane 3. Green - Lane 4 ("trucking lane").

Key: Blue - Monday. Red - Friday.

Here it seams the data is telling quite a compelling story. The flow on each of these days, rises quite rapidly in the morning time, but notice that the peek flow occurs 40 minutes apart on each of these days (6:45am on Monday and 7:25am on Friday). I believe this 40 minute time gap can best explained by the majority of cars on the road ways are people going to work. Mondays are a great day to kick off the week, and it seams most people try to start the week off right by trying to get to work early or on-time. Another interesting point of note, is the leaving times in the afternoon on both these days. On Monday we see people stay off the roads for a bit longer then on Fridays. Mondays peek Flow is seen at 5:10 pm. Friday however, we see a triple peek; Once at 2:45 (slackers), 3:40 (conservative effort workers) and again at 5:20 ('Over time' Workers). Overall the peeks occur earlier on Fridays then they do on Monday. The peeks are also more amplified on Friday, then they are on Monday.

Notice: the leave time in general is much more scattered, as people can usually leave there "work" at a more flexible time, then when they must arrive.

Assumptions: This is only for one highway, at one location on the highway, during one Monday and one Friday, However this is going to be true in all highways all across the world.