I’ve put together some graphs of the traffic studies performed by project engineers in October 2008. These data are taken from the Functional Design Report Draft that is available on the town’s website (http://www.arlingtonma.gov/massave/). In an effort to appease project opponents, engineers also collected traffic counts in April 2009. The April 2009 counts came in lower than the October 2008 counts, thereby reaffirming the October dataset as a representative if not conservative measure of Mass Ave traffic in East Arlington.  Note that where 2000 vehicles are shown as capacity that means there are two travel lanes, where 1000 vehicles are shown as capacity that means there is one thru travel lane.

There are four graphs, each depicting a travel direction at an AM or PM peak travel time. AM peak hours are weekdays from 7:30-8:30 and PM peak hours are weekdays from 5:00-6:00. In the graphs, the design standard or max capacity is represented by the right-most bar in yellow. Each lane has a designed capacity of 1000 vehicles an hour. Current peak traffic volumes are shown as blue bars and the purple bars show expected peak traffic in 2018. Expected traffic was determined by assuming a traffic growth rate of 1% compounded annually, as specified in the engineers’ report. As you can see in all areas of the corridor, traveling both directions, and at both AM and PM peaks the amount of traffic is well less than the designed capacity not only presently but also in 2018.

Thus, we have a road in our neighborhood substantially over-designed for peak travel and vastly over-designed for the other 22 hours a day on weekdays and all weekend long. Mass Ave is more than a commuter corridor and should not be designed solely around peak commuting times. Mass Ave is our main street and we should treat it with the pride and context sensitive design that a main street deserves. I really wish opponents would recognize this fact—that not only are their concerns about traffic being addressed, they are being addressed excessively and to the detriment of our neighborhood. The original plan still had a capacity in excess of current and 2018 expected traffic, yet by reducing the number of two lane sections relative to the current plan, it had better pedestrian safety and most likely would have better enhanced Mass Ave as a neighborhood center and destination.

Despite my disappointment with the current plan, I support it because many key elements like pedestrian bumpouts and bike lanes remain and because I recognize the need to compromise with opponents. Nonetheless, opponents would like to see four lanes of traffic, something that would not only be woefully over designed, would need extra right of way, and completely ignore the state law which requires bicycle accommodation. We have made compromises, and yet opponents will not be satisfied until a de-facto highway is put in place for Mass Ave. We need to stand firm and not let that happen.