405 Northbound - Monday V.s Friday Traffic Comparison

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.
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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.