Im here nearly every day to commute via the 65, 66, or by bike, and the biggest issue with any traffic congestion is the pretty terrible light cycle timing. Doing my best to annotate on an iPhone on an old image but the problem is that there are a lot of backups trying to take the left onto Brookline from Rt9 in the AM, so everyone ignores the "Right Only" at High St. and continues straigh through the bus lane (Green) to get around the left turn traffic (Red). This turning traffic builds up a lot because Washington St from Brookline Village releases onto Rt9 at the end of the green cycles for Brookline Ave and the Pearl/Walnut intersection leading to the Rt9 traffic at Washington Int. getting realeased into already full lanes on a red. What would go a long way to relieving this is if drivers coming from Rt9 realized they could take the legal right onto High to then go left on Walnut and straight through to Pearl and then Brookline (Blue). As it stands these side streets only have a few cars each cycle on them and are basically empty, and with the current signal timing, doing this maneuver would get those going to Brookline Ave through the area quicker since its on green or about to go green when they get that Washington green (convoluted sounding I know).
View attachment 65250That being said, reconfiguring the timings and cycles to better suit the traffic patterns of the given time of day as originally stated would be the best remedy of the situation. Rt9 at High St should go red before Pearl/Walnut and Brookline, leaving them green to empty out traffic before letting Washington out onto Rt9 with Peal/Walnut green (westbound can simultaneously head up Washington) to let Wahsington traffic fill the Queue then turning red briefly for cross traffic (whilst Westbound is released up the Rt9 hill) then start from the top with green at Brookline for Rt9 eastbound cascading to Peal/Walnut and High St. This would keep queues from overflowing and blocking the next cycle and is much better in line with where the AM traffic volumes are than the existing timings. PM is way simpler and not too bad. The backups happen more with the Cypruss intersection than back here and the bus has a clear path because few people are heading right up Washington.
Hopefully what Im getting at makes sense and I described it properly. Kinda rushed the explaination