Bus Lanes Going Live

Continuation Thread

For more on this issue, please see Understanding the New Bus Lane.

Update, Thursday, November 15 Morning

Finally, the signals on Mount Auburn and Fresh Pond are working as intended. Many people are avoiding the area and that made traffic quite light, but the improvements are very real.

Roughly 20 cars were getting through in each light cycle on Mount Auburn this morning, compared to only one or two yesterday. At 8:30AM, the total time from Belmont Street through Fresh Pond was down to 4 minutes, compared to 20 yesterday. After 8:30, a work crew took a lane from the intersection. Their project to replace a MBTA utility pole downed by a motorist should be done before Monday. Traffic was a little slower with that lane gone, but it did not back up past Aberdeen.

Conditions on Fresh Pond Parkway seemed very good, with plenty of capacity to receive motorists crossing or turning off of Huron Avenue.

There are some remaining opportunities for light timing improvement which we will attempt once it is clear that the current round of improvements is finally stable.

Please continue to provide feedback. The more specific the better. If you were delayed unreasonably, I want to know exactly where and when so we can provide meaningful guidance to the engineering team.

For those who interested, the challenge has been programming the sophisticated M-60 Siemens Traffic Controllers. These devices are complex enough that many professional engineers cannot keep with the training requirements for them. Yesterday, DCR had the right specialist make the necessary corrections.
Observations at the main light from 7:52AM appear below. Note that around 8AM, there is a problem with left turning parents driving their kids to Shady Hill school. We’ll give this continuing attention.

Update, Wednesday, November 14 Evening

Tuesday’s efforts did not provide the promised improvements.

Traffic conditions were slightly better but still terrible on Mount Auburn this morning. Transit times from Belmont Street to Fresh Pond Parkway reached as high as 20 minutes. Driver frustration was high.

Light timing was still the problem.

Pine Ridge Technologies is the contractor whose light programming efforts have so far been unsuccessful. Ocean State Signal — a more specialized firm — was brought on site today to redo the timings.

I will be on site tomorrow morning to continue monitoring the results.

Update, Tuesday, November 13 Afternoon

A series of human errors in signal programming has made the last 10 days miserable on Mount Auburn Street and Fresh Pond Parkway.

Today’s commute was especially disastrous as the two close-together lights at Coolidge Avenue and at Fresh Pond parkway were 100% out of phase.  Only a few cars could get through in each cycle — the number of cars that could fit in between the two lights.  These out-of-synch lights effectively blocked traffic and cars were backed up well in to Watertown and Belmont.

To make matters worse today, a utility pole got knocked down in an accident last night.  Crews had to take a lane between Coolidge Avenue and Fresh Pond Parkway to support the bus trolley lines with a special truck.   This further diminished the capacity of the intersection.

Last week was bad too.  An unexplained software problem, possibly related to the transition to daylight savings time, caused the lights to be partially out of synch.  An attempted fix last Thursday was botched by a subcontractor, apparently making matters worse not better.  However, the top traffic engineer of DCR was on site to oversee fixes today and believes that tomorrow’s commute should be much better.

I will continue to monitor the intersection tomorrow and DCR’s top traffic engineer will also be on site as will engineering staff from the City of Cambridge.

The video below shows the traffic signal timing this morning that was disastrous. It was filmed from the north side of Mount Auburn Street opposite the opening of Coolidge Avenue.

Text of Email this afternoon from Tegin Teich, City of Cambridge

To the interested parties of the Mt. Auburn Bus Priority Pilot,

As many of you are aware, problems with the DCR-owned signals at Coolidge Ave and Fresh Pond Parkway resurfaced last week. We understand that these issues impacted all users (drivers and bus riders) on Mt. Auburn Street and Fresh Pond Parkway. The signal timing issues were exacerbated by other traffic conditions, such as the crash on 93 last week that affected traffic regionally.

We have been assured that DCR brought the Mt. Auburn Street and Fresh Pond Parkway signal back into coordination and working order today. This should ease challenges experienced by bus riders and drivers from this point forward and we will be monitoring to ensure that is the case.

The bus lane pilot works reasonably well when the signal timing was working correctly, as was the case during the week of October 29th. We received many positive comments from all kinds of users that week, as well as some informative critiques that will help us tweak the design to work better.

We will continue to monitor the conditions to ensure that the signal timing works and the project functions as intended. Following this, we will continue to observe and note unanticipated effects, make minor design modifications (if needed) to improve the bus lane pilot project, and begin assessing the impact of the bus lane pilot on all users before making decisions on next steps.

Thank you yet again for your patience as we focus on fixing the issues at hand before turning to an evaluation of the bus lane itself. This is a multi-agency project and requires coordination among many entities for its success. Our goal remains the same for the pilot: to significantly improve travel for bus riders without negatively impacting driving travel times. It is very important that you continue to share your feedback so we can have the best outcome as possible for all Mt. Auburn St. users.



Update, Friday, November 9 Afternoon

The changes made on Thursday were not fully successful. Mount Auburn Street East Bound throughput improved somewhat, but timing errors were made that caused backups on Fresh Pond Parkway.

The team hopes to have the system working well again by Tuesday mid-day.

Aggressive monitoring will continue until the changes are working right.

Update, Thursday, November 8 Afternoon

An overloaded truck hit the ceiling of the O’Neil tunnel this morning causing the whole of I-93 South to close, backing traffic up to Wilmington. Much of that traffic took other routes, causing traffic jams all over the region, including on Fresh Pond Parkway. Traffic conditions were horrible at the intersection that we have been working so hard to fix.

The changes implemented this morning should work better tomorrow when normal regional conditions are restored.


Update, Thursday, November 8

As of 7AM this morning, the fixes to synchronization had been made. A DCR subcontractor was on site monitoring the situation, as was I. Motorists were getting through in 2 cycles when traffic started to build after 7:30. Fairly typical for the area — roughly 3 minutes from Aberdeen across Fresh Pond Parkway. Much better than the 9-10 minutes I tested the day before.


Update, Wednesday, November 7

Week three of the Mount Auburn bus lane roll out has been rough. It appears that the light timing fixes that were made two weeks ago drifted out of place and traffic conditions deteriorated considerably.

The key timing issue is between the two lights closely spaced at Coolidge Avenue and the main Fresh Pond parkway intersection. If they are not fully coordinated, then the waits build rapidly. Testing rush hour driving conditions today, I experienced a full 9 minute delay driving between Aberdeen Avenue and Fresh Pond. When I reached Coolidge Avenue, I observed that for the majority of the green signal that the first light had, the second light was red.

DCR is aware of the problem and has promised a fix today.

There are a number of possible ways that the lights can drift out of synch and it has been an historical problem that goes back before the bus lanes. We are going to push for a hard coupling of the lights to improve reliability. This permanent fix will take time.

Update, Tuesday, October 23

The first day of the new lanes did not go as well as hoped. Many bus riders reported a positive experience, but auto drivers were backed up.

There was an error in the signal timing that backed up auto traffic badly. That error has now been fixed.

There are two lights very close together along Mount Auburn — the light at the main Fresh Pond Parkway intersection and the one immediately before it, the light at Coolidge Avenue. These two lights must be very carefully synchronized so that the vehicles coming out through the Coolidge light can get out and across the the main intersection. If vehicles cannot go through the Coolidge light when it is green because the second light is red and the storage is already full, then the whole system gets backed up. This is a condition that occurred from time to time even before the changes.

The two lights are not physically connected. Rather, they both get the exact time of day from GPS satellites and then run on programmed cycles. The cycles in the two lights have to be programmed so that they work together with reference to the shared time of day. When there is an error in that programming as there was on Monday, delays can build exponentially.

The error was fixed on Monday and traffic flowed better on Tuesday. Tuning will continue on Wednesday to optimize performance for both cars and buses.

Traffic engineers from the City of Cambridge and the state’s Department of Conservation and Recreation (which controls the two critical lights) will continue to monitor the performance of the new system.

If you have experiences — good or bad with traffic flow that you want to post here, please include the date and time.

Four years ago,  Representatives Hecht and Rogers and Senator Jehlen and I started a conversation about how to improve the  71 and 73 bus service on Mount Auburn Street, focused especially on the bottleneck in Cambridge in front of the Mount Auburn Cemetery.  That conversation and the efforts that have come out of it are chronicled in a long thread on my website.

The conversation is finally starting to result in real changes.  Dedicated bus lanes have recently been painted on Mount Auburn Street in that stretch.

And, on Monday morning, new signal controls that turn green for buses when they approach will go live at the two closely spaced lights where Mount Auburn Street crosses Coolidge Avenue and then Fresh Pond Parkway.  Transit priority signals are already working at the lights at Homer Ave and Aberdeen Avenue.

We hope the changes will make a big difference for bus commuters (the majority of commuters in that stretch of road), without slowing down car drivers.  This will be possible because signal timing changes should increase overall throughput on Mount Auburn Street.  Cyclists will be permitted to use the bus lanes.   More changes will come over the next year or two that will continue to make the intersections in this system work better and more safely for everyone.

The City of Cambridge has been doing a great job explaining the changes — see their website here which includes plans and informational videos.

The project has required intense collaboration between the MBTA, the City of Cambridge, the Department of Conservation and Recreation. We are very grateful for all of their efforts.

Let me know how you feel the changes are working!

Future Plans

There is another wave of changes planned for the future that should benefit all travelers on Mount Auburn Street – geometry improvements at the huge intersection by Mount Auburn Hospital.

In order to give the heavy Fresh Pond Parkway traffic the green light time that it needs to get through that intersection, traffic at Mount Auburn Street waits at a red light. The total amount of time in the light cycle is limited because of the poor geometry of the intersection. The roads cross at an angle so the distance between stop bars is unusually large – cars take a long time to get through the intersection and frequently get stuck in the middle causing gridlock. Pedestrians also need extra time to cross.

Tightening up the intersection will allow more green time for all traffic to move through it. Scheduling for those changes is still in flux, but we are pushing to complete some of them in the next construction season.

Published by Will Brownsberger

Will Brownsberger is State Senator from the Second Suffolk and Middlesex District.

Join the Conversation


  1. We have been driving along Mt Auburn for years en route to my son’s fencing club in Brighton. This new dedicated bus lane has made the commute even longer. Once we turn left off Aberdeen onto Mt Auburn, the cars get stuck from Brattle St to Coolidge because of the lane restriction. We’re hopeful the lights will be better timed or some other improvements will be made to ease this newly created congestion.

    1. I agree with Alisa, that during the recent commute on Friday, that traffic was worse for drivers. I am for promoting public transportation, but that 1000 meters between Aberdeen and BB&N on Mt. Auburn is the most congested section on my commute between Belmont and Boston. I hope as drivers become use to the new bus lane that an already bad section does not become worse.

  2. Looks good, and I now see the red coloring of the right bus Lane, but a lot of people still confused about which lane to turn into when taking a left from Belmont St onto My Auburn. Lots of near crashes.

  3. Will,

    We regularly drive from Belmont into Cambridge, taking Belmont street to Mt. Auburn street. We’ve experienced the new lane markings, and how drivers respond to them. In short, they ignore them. In particular, on Belmont Street at the Mt. Auburn intersection, the right lane is marked with a right-turn-only arrow. Many (most?) drivers still turn left at that intersection from the right lane.

    Continuing on past the Mt. Auburn Cemetery, your write-up says “dedicated bus lanes have recently been painted on Mount Auburn Street.” Again, as far as we can see, those signs are completely ignored.

    There is strong motivation for cars to use the right lane, because there are stopped cars in the left lane waiting to turn left across traffic.

    The plans seem to assume that some drastic changes in driver behavior will happen “automagically.” I’m not sure how realistic that is–particularly since commonsense suggests to drivers that being channeled into a single lane with left turning cars will result in a slower transit than being able to use both lanes.

    The goal is a good one, but I wonder whether the current plans will be successful.

    1. This! While traffic looking to continue on Mt. Auburn east-bound across Rt.16 sits at the light, there is no ability for traffic behind the first (green!) light to access the far right hand lanes and inbound on to Rt. 16 without ignoring the bus lane designation. Crazy.

      1. I don’t think that is correct: There is no bus lane in the segment immediately west of Aberdeen. The bus lane is not continuous.

        Correct me if I’m misunderstanding your comment.

  4. I rode the 71 on Thursday morning into Harvard (Oct 18). I had been closely watching the lane markings over the past month, and I was pretty confused by the story they told. But now that the bus lanes are painted and I see it in operation, I think I understand. I don’t have data, but it definitely felt like the bus moved a lot faster in that area than before. Giving the bus priority just until it gets to the bus stop across from Star Market is so smart!

    I’ve ridden the outbound direction a few times as well, and it seemed to go fine. I’m still wondering if the large amount of inputs (2 lanes from the big intersection, plus another lane from Brattle street) will cause trouble, but I haven’t seen that happen yet.

    Overall, I think this is a big win for the buses and I’m hopeful that it translates into less bunching and more consistent schedules, on top of the improved trip time.

    1. Quick update on this: the outbound direction has continued to be a smooth trip through the star market area, coming from a weekday rider. Send my fears were unfounded.

      One thing I did just see tonight though: a driver ahead of the bus on Mount Auburn Street thought that the stop signs for Brattle Street applied to them. As a consequence, the bus driver had to brake pretty hard due to the unexpected stopping. If that’s a common problem, maybe an angled blinder on the first stop sign would help?

  5. I am a regular bus commuter and occasional car driver on the 73 route. Agree with those who have noted the lack of observation of the new lane markings by drivers. My driving commute through there on Thursday was about normal (took forever) but my bus commute on Friday was only about half it’s normal time! 20 min to get to Harvard from the Payson stop on Belmont Street was such a relief from the usual 30-40 min! It was really exciting.

    As a driver though I am concerned about the frequent transitions between lanes that are now required on the stretch of Mount Auburn next to the Star Market. I realize there isn’t more space there to expand. But maybe that left turn only lane at Aberdeen could be changed back to either/or??

    I really appreciate your long term advocacy on this issue. It’s become a huge problem and really affects the quality of life of many people!!

    1. Yes, I noticed this, too. Drivers really don’t seem to pay attention to signs around her. Witness the Common St. southbound through Trapelo intersection. One despairs, sometimes!

  6. This is cool! I look forward to seeing how it works and will be sure to offer feedback!

  7. Will this is great as long as it does not make these roads to congested to the m/v drivers. I hope this is monitored closely and it’s better for everyone. There is a balance that must be reached not causing major tie ups. I have my doubts that this will work in this area but hope that it has been studied and will work

  8. West-bound Brattle used to merge with west-bound Mt. Auburn. This was changed to a stop sign on Brattle several weeks ago, and immediately became a disaster during evening rush hour. Instead of alternating cars between west-bound Brattle and west-bound Mt. Auburn, only one Brattle St car for every two or three Mt. Auburn St cars proceeds, due to the stop sign. With Brattle St backing up several blocks past Fresh Pond Parkway, I’ve started using alternate routes home. I guess making traffic horrendous, and hence pushing drivers to alternate routes is one way to make Mt. Auburn traffic to appear to improve.

    West-bound Cambridge St, just prior to Quincy St in Cambridge is a slalom course for a few blocks, as the lane zigs back and forth through turn lanes, alternating parking, etc. While the Mt. Auburn St bus lanes pale in comparison, the need for extra lane changes may increase the accident rate, and slow traffic even more. Time will tell, but I’ve already started using alternate routes to avoid the Mt. Auburn St redesign.

    I’m sure the bus and bicycle traffic will improve with dedicated lanes, so the project will likely be declared a success, much like the Belmont St redesign. However, I’m no longer able to make a left turn onto east-bound Belmont St during rush hour, due to the continuous flow of single-lane traffic, so I shifted to alternate side-streets to get onto Belmont St. Crippling Mt. Auburn St makes my need to get onto Belmont St less important, as I use alternate routes on days that I need to drive.

    There are certainly no simple answers, but the Belmont St and Mt. Auburn St traffic “improvements” are frustrating, at best.

    1. We’ll keep working it. Agreed that there are no simple answers — there just isn’t enough asphalt for all the traffic these days. That’s why we have to work to make transit work better so that more people will ride it. This is part of that.

      1. Cycling, buses, and walking can and do work on days when I have a simple commute, but does not account for my “normal” commute, which often includes hauling soccer and/or hockey equipment, running errands, transporting one or more kids, etc. as part of my commute.

        We need roadways that work for cars also.

        1. Roadways that prioritize cars scale poorly. We need quality public transit infrastructure, which scales much more efficiently.

      2. There may not be enough asphalt, but implementing improvements that make things worse is not an option.

        The merging/alternating that worked well for a long time at the above referenced location, is not a stop sign creating a mess. Again, not thinking things through in a reality-based framework. Please stop punishing people to make things [email protected]!

  9. Regarding the intersection of Belmont st eastbound at Mt Auburn st: for, say, 3 hours out of 24, buses serve a critical need for inbound T commuters, and the dedicated serves that need well.

    For the remaining 21 hours you’ve now created a back up because only one lane can be used to make the left turn; the other lane sits empty for the vast majority of the day. You’ve now created a 2 light cycle potential, with additional pollution and aggrevation. (Please correct me if I’m wrong)

    How does that make sense?

    1. I have to agree with this comment regarding the bus/bike only lane at the intersection of Belmont & Mt. Auburn. Is one permitted to turn RIGHT at any time of the day or night from Belmont onto Mt. Auburn? Also the double left arrows indicating that a single lane of cars from Belmont St can turn left into both lanes going East on Mt. Auburn seems to set up an unfortunate confrontation between auto and bike/bus.

      1. Continuing on this same intersection, when someone wants to turn left onto Holworthy,this is surely creating a significant back up, because we have only one lane to turn left from; 23 hours in the day, this makes no sense.

        The same logic applies at Cooledge ave. eastbound on Mt Auburn st. We drivers are restricted from using a lane, the new bus lane, despite the fact that 23 hours a day it serves little to no added benefit to mass transit.

        This is just wrong thinking.

        1. 23 hours a day, there is no traffic jam and one lane is enough for drivers.

          It’s all about rush hour and during that hour, we have to favor the bus riders who constitute the majority based on traffic counts and are much less comfortable while waiting than the drivers. Those buses are packed — in fact, since they have low seat counts, they are the two most packed buses in the whole MBTA system!

  10. The bus commute is so much faster in both directions! As someone riding home with an impatient and hungry toddler I am acutely aware of how long the ride is, and it has made a difference. I really appreciate you studying this issue and trying to make positive changes. I also ride in with my husbands some mornings by car and it doesn’t seemed to have slowed the driving time for those of just driving straight down Mt Auburn. I do worry about bicycles and buses sharing a lane- I overheard a conversation between bus drivers and they seem concerned about the safety of the cyclists especially when turning.

  11. Will….sorry, but these new bus lanes really frustrate me! Between bike lanes and now bus lanes, the automobile traffic has come to a standstill! I understand we want to encourage public transport and less fossil fuel use…. but the real answer is much bigger than just limiting auto space in Belmont, Watertown and Cambridge!
    I can’t do my job without my car…. and now the bus and bike lanes have added significant time to my having to sit in traffic just to make a living.
    Sorry to sound like a jerk, but it’s judt added to my stress level…
    Donna Brescia

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