Saturday, August 23, 2008

Traffic: Route 9 and Beyond

I've been thinking a lot about traffic, or more precisely, traffic congestion, lately. I'm afraid I'm going to have to discuss the nitty-gritty details of traffic volumes, turning movements and intersection capacities, later on, but it's all for a purpose. Namely, to illuminate a possible future and to give us a chance to think about just what kind of future we would like to be planning for and whether or not the two correlate.

I spent the better part of a week forecasting and analyzing the potential traffic conditions on Route 9 focusing in on the section between Brookline Avenue and Cypress St. I began by looking at the traffic study done by the consultant for the 111 Boylston St. development. This study estimates the number of new vehicle trips likely to travel to the site, predicts their likely travel route and analyzes the function of the intersections these vehicles will travel through in year 2013. Building on this information, I have forecast and plotted the potential traffic impacts of continued commercial development at the other available sites along Route 9 in this area, postulating that it would be built-out to the full amount allowed under current zoning and assuming it were similar in use to the 111 Boylston St. development. This has been an enlightening exercise, one that has led me to some interesting conclusions which I will describe in more detail later.

All the while when I was working on my "build-out traffic analysis", I of course experienced traffic congestion without even getting into my car. Just going about my daily life, I experience the nearly constant problem in Coolidge Corner that culminates in the log jam of cars traveling north on Harvard Street blocking the westbound Beacon Street flow, long after the light turns green. This phenomena results in some colorful words and gestures, as horns blare and agitated drivers execute maniac moves. Pedestrians, defiantly responding to their walk signal, (for which they have patiently waited), trudge through the middle of this, unconcerned about the plight of the cars stuck in the middle of the road. Note that, I said cars, not drivers. Once behind the wheel, our isolation, anonymity and sensory deprivation often cause us to act and be treated in ways that would never occur if we were face-to-face. Riding a bike is another way I experience congestion without getting into a car. It is often a game of chicken, where one needs to constantly second guess what a driver might do and they all behave differently around a bike.

Just to add to the immersion factor, I have been reading the fascinating new book "Traffic: Why We Drive the Way We Do and What it Says About Us." by Tom Vanderbilt. What this book lacks in depth it makes up for in breadth, and one is able to come away with a few over-arching conclusions, the most persistent of which is that despite all the tools and aids we erect to guide, regulate, enhance and protect ourselves, our human fallibility leaves us vulnerable, as we come up against our limited capacity to perceive accurately, evaluate risk realistically or act rationally. Driving is an unpredictable, uncontrollable, and unmanageable and therefore dangerous pursuit. Controlling it or managing it is only partially successful because of the random factors of human psychology.

My favorite line in the book was this, "Parking is the gate way drug to full blown traffic abuse." A phrase much akin to Fred Salvucci's "Parking lots are fertility drugs for cars." My favorite section was about Hans Monderman, the Danish traffic planner who understood that it was the world of cars that was the guest in the human world of towns and cities and that by removing all traffic signs and designing roadways for slower speeds he could insert uncertainty into the driving experience, forcing drivers to expect the unexpected. Therefore to travel safely they must interact with pedestrians, bicyclists and other cars in a new context of shared space. To illustrate his point he closed his eyes and walked backwards into a traffic square of his own design and as predicted, the autos gently pick there way around him. As for "Traffic's" lack of depth, the nearly 100 pages of detailed notes offer enough source material for follow-up to anyone seriously interested in any of the many many research topics he touches upon.

But back to Route 9. The Article 15 debate focused our thoughts on the potential traffic impacts from the 2 Brookline Place development, thanks to Hugh Mattison, the Article's petitioner. The Article called for lowering the amount of required parking for this new, large and traffic intensive development, urging a shift towards utilizing the adjacent transit resources, as was originally intended by Town Meeting. We tried to tease out the nexus between vehicle trips and on-site parking. Concerned citizens living nearby wondered just how much of that new traffic would travel on their streets, or how they would be able to get out of their driveway as cars stacked up at a newly installed signal. We heard consultants predict how many new vehicles will traverse our crowded roadways to visit and work here and which intersections will be affected. They described what intersection improvements were necessary to mitigate those impacts.

The bottom line was that, despite a significant underestimate of volume, (the initial estimate for 2 BP was a total of 2,800 daily trips, for a 260,000 sq.ft. facility, compared to the total of 2,400 daily trips for a 66,000 sq. ft. facility at 111 Boylston St.) the intersection with Brookline Avenue and Route 9 cannot handle the demand for left turns off of Route 9 heading to 2 Brookline Place in the morning. These vehicles, once on Brookline Ave, will then need to turn left onto Pearl St., a new traffic light will be necessary at this intersection. Pearl St. itself will be strained, as it is a narrow roadway with parking, frequent double parking and many exiting and entering driveways. It is acknowledged that the Gateway East roadway improvement, (a major construction project involving State and Federal dollars), which lengthens the jughandle and aligns Pearl and Walnut St. into a four-way intersection with Route 9 is necessary to accommodate the traffic associated with this project. This is because it will allow eastbound vehicles to turn left, directly onto Pearl St., thereby solving the Brookline Avenue/Route 9 intersection malfunction.

These problems are near-term and close-in and even if these congestion difficulties are successfully managed, there are also the further afield "ripple" effects of the additional thousands of daily trips added both to the through traffic volumes on Route 9 and spread out through many already congested intersections, such as School St./Cypress and Washington. More through travel on Route 9 means there are less "gaps" to accommodate increasing volumes of turning vehicles, as these two demands work against each other. The hoped for "fix" of re-timing the signal that is often suggested for failing intersections offers little hope in this situation as all competing volumes are equally high. Changing the timing to allow for a higher volume of a particular turning movement will add additional delay will to Route 9, causing backups through succeeding intersections. Other major developments are happening just over our borders too, such as the re-development of the site of the old Omni supermarket in Chestnut Hill which increase vehicle trips on Route 9 substantially. Brookline will also be impacted by additional Longwood development and building over the air rights of the Mass Pike in the Fenway. These additional developments were not included in the traffic analysis for 111 Boylston St.

As everyone recognizes, Route 9 is already a heavily traveled roadway, carrying as it does approximately 31,000 vehicles a day. Anyone who uses it regularly for commuting knows you are just going to sit there, spewing pollution, wasting fuel and contributing even more to global warming than you might otherwise have had to, had you not been delayed. All this congestion results in poor air quality, increased greenhouse gases, increased stress, and lost time and money (for both individuals and businesses), negatively impacting our health, environment and economy. Desperate drivers begin diverting through neighborhoods to seek a quicker route.

As one approaches the city on Route 9, the delays increase due to the combination of heavy through travel and the increased frequency of cross streets and driveways with high volumes of crossing and turning travelers. What began out in the suburbs as a controlled access four lane arterial has become something of a hybrid roadway, still with its median barrier, but the intersections are less like a highway intersection with exit ramps and flyovers and more like a city cross street. Yet the roadway is still needed to carry its high volume of through traveling commuters.

Into this setting, let us consider the consequences of developing or re-developing, the other G 2.0 parcels on Route 9 near Cypress St. To orient you that would be the Audy Gas Station, and the 303 Boylston St. site on the north side of Route 9 and the Volkswagen Dealer, a small Electric sub-station and the U-Haul on the south side. The rest of the land along Route 9 between Cypress and Washington is zoned either G 1.0 or M 1.0 (CAM) and was not included in my "build-out" analysis.

The rough estimate of additional peak hour trips associated with the build-out would be:

AM Peak Hour: 1, 037
PM Peak Hour: 1, 355

Peak hour in this case refers to the peak hour on Route 9, not the peak hour at the development site, which because it is a medical office building will be busy with patients coming and going all day. These numbers may be too high, because they are higher than counts taken locally, but I also believe the consultant underestimated the "background growth" when they did not include the large additional developments in the area and assumed a growth factor of only .5% per year in volumes. Perhaps high gas prices will help achieve this low growth level. While these numbers alone may seem distressing, what is particularly problematic is the fact that at any given time at least half of the vehicles coming or going will need to reverse direction in order to access or leave their point of origin.

Despite the fact that these sites are very near to the Brookline Hills T-stop, they are valued and perceived by potential builders as auto-oriented building sites. Our current zoning code, with its on-site parking requirements and separation of uses, encourages and reinforces these perceptions. The resulting proposals are then not surprisingly best suited to a suburban setting with good highway access and plenty of parking to accommodate everyone accessing the site via automobile.

In the case of the land near Cypress St. and Route 9 it was estimated that 65% of the people coming or going to the site would be from the west. So, in the case of buildings on the north side of Route 9 accessing the site necessitates a U-turn. The 111 Boylston St. consultant predicted that everyone would achieve this maneuver at the Walnut St. jughandle. This requires the reversing vehicles to swing around the jughandle then turn right onto High St. and immediately left onto Route 9 at the Washington St./Route 9 intersection. This intersection was already functioning at LOS D in 2007 during the AM peak hour. With the addition of 111 Boylston it is predicted to function at LOS E. With higher through volumes on Route 9 and/or High/Washington St. the LOS will further degrade. This is before we add in any additional development on the remaining Route 9 parcels. In addition to the limiting factors of high through volumes on Route 9 this intersection is severely constrained in another way. The closeness of the High/Walnut Street intersection to the Washington/High/Route 9 intersection means that only about 3 left turn vehicles can fit in the left turn lane. Two source lanes of traffic are competing for those three spaces, cars traveling north on High St. and those folks who are reversing direction from the jughandle. With high demand from both sources, it becomes increasingly difficult for the jughandle cars to ever get into this lane. The entire signal cycle length at Washington/High/Route 9 is 90 seconds. That means there are 45 cycles per hour. 45 times 3 cars per cycle and this intersection can "process" at a maximum (if everything works perfectly) of 135 left turns. The 111 Boylston St. study predicted a demand of 129 left turns here during the AM peak hour. The project developers for 111 Boylston St. are contributing some mitigation dollars to the Gateway East jughandle improvement, which is postulated to aid the functioning of this intersection by allowing more space for vehicles waiting to make the left onto High St. This is a marginal improvement to the basic limitation of the left turn at Washington/High/Route 9.

For my build-out analysis, instead of assuming that everyone who needed to reverse direction (east to west) would do so at the jughandle, I anticipated the capacity limitations of this intersection and assumed that half of the people (124 during the AM peak) would instead turn left at Cypress, (no easy trick either) then right on Davis and then right on Route 9. This circuitous route is not self-evident and diversion attempts will, until they are learned, result in circling and wandering before a new route is learned. This alternative route is likely to be used even more than this, given the degree of difficulty I have described at using the left turn at Washington/High/Route 9. Half of those not diverted to Davis are still going to be trying to turn left at the failed Washington/High/Route 9 intersection, or will be executing illegal U-turns or finding other routes.

For development on the south side of Route 9, those leaving the sites who wish to return to the west will simply turn right on High Street, right on Walnut and then either right on Cypress or continue straight. I estimated an additional 490 vehicles in the PM peak hour on Walnut. While these vehicle numbers may be high, they nevertheless illustrate the inevitable result of additional auto-dependent development of these particular parcels, namely, the reverse direction move will be accommodated on Davis and Walnut Streets, two residential streets that are already suffering the physical and environmental assault of too much traffic.

Other roadways that serve as limited access commuter routes, such as Route 1 in Dedham for instance while also accommodating intensive retail development has done so by providing an elaborate system of controlled access ramps, frontage roads and signalized turnarounds. Clearly, we are not looking to develop to this intensity, but it illustrates the elaborate engineering machinations necessary to accommodate the disparate functions of through travel, localized access and intensive roadside development.

Some would choose to simply disregard the needs of the through traveler, taking "possession" as it were of "our part" of Route 9. However, this is a short-term and self-defeating proposition. Mobility for commerce, such as delivery trucks, tradesmen, customers and employees are all essential to the fabric of our economy. By developing highly intensive auto-dependent commercial uses on these particular parcels we are causing a much greater problem than we are solving. As currently configured these sites are attractive to business because of the amount of traffic that passes by. This is why a use like the VW dealer, while we may not think it optimal, is at least in terms of function, sensible. It is seen by a lot of people, but does not "generate" a great deal of trips. Same goes for the gas station. Gas stations aren't destinations and pull their customers from the passing flow, thereby not adding to existing volumes. Audy's has its own difficulties with the driveway on Cypress being so close to the intersection, but that's another issue.

But, it doesn't have to be this way, there are other alternatives, which are more in keeping with the goals outlined in our Comprehensive Plan and in harmony with a more sustainable vision for Brookline. This corner, Cypress and Boylston St. has some of the bones necessary to become a walkable, mixed use "village" that takes advantage of its T access and allows nearby residents to fulfill some of their daily shopping needs without driving. Altering our zoning to more precisely define mixed use guidelines and to devise an overall vision for public realm amenities will allow an alternative vision to take shape. Thereby, reducing the negative traffic impacts on our neighborhoods and Route 9 itself and maximizing the value of our transit resources and residential density, making for a more effective and longer-term economic development strategy. These goals were loosely stated in the Comprehensive Plan and further refinement could help us articulate a creative and specific plan for a new neighborhood commercial area. The Town will be seeking a smart growth planning grant from EPA or other sources to do just that.

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