Cascading Affect

With any commute you come expect certain points along your route to move slowly. A series of lights or three lanes going into two or merging of traffic from another major route tend to create slow points. This week I was heading and was about a mile from one of the major slow down points created a perfect storm, the merger of traffic from three lanes into two right at the point where two major routes enter. Complicating the flow are two lights just after the second merger and the narrowing of the lanes. The traffic suddenly slowed and then crawled well before the normal place.

It took nearly minutes to get through the area that even in heavy traffic normally takes five minutes. I thought that there was a major accident. As I approached the pair of cars with their flashers on I could see Arlington backed up as far back as I could see, about two miles. Looking down the beltway, the first major set of mergers, I could see northbound traffic was crawling along from the south but flowing well after the Arlington exit, and the southbound traffic was crawling along from the north in a similar manner. The traffic coming down the two ramps of the beltway were so backed up that traffic was backed up so far that the deceleration lane was overflowing onto the expressing, thereby functionally closing down one of the four beltway lanes. The second major merger was also a mess.

Expecting a significant accident I shook my head when I saw the cause. The cause was one car rear ending the car in front just beyond the merger of the other route and the three lanes into two. It was clear that there was little damage. No crumpled panels or bumpers. No broken lights. They speed of impact was likely below 15 mph. Rather than pulling off to the shoulder both cars sat there, drivers sitting in their cars, waiting for the police. Though the police will take the report it is likely they would be told a) the police did not need to be called for this accident and they should have just exchanged information, and b) that they should have pulled off to the side of the road to exchange the information.

Sitting there behind their wheels waiting for the police for something that did not need police involvement had a cascading impact.