Cambridge Civic Journal Forum

May 18, 2012

Reports on December, 2011 fatal truck/bicycle collision

(Note: this post has been updated since first placed online, because readers have asked for images to clarify the location and details of the incident. Also see comments following this post. Review of the reports, images and comments has led to some changes in the post, as well.)

The MIT student newspaper, The Tech, has obtained and posted copies of some of the police reports on the truck-bicycle crash on Dec. 27, 2011 which resulted in the death of an MIT graduate, Phyo Kyaw, ’10. I comment here on the Tech story about the crash, and the police reports it links to.

I study bicycle crashes — it’s part of what I do in my profession, but I offer the following comments for free as, I hope, some small service to the MIT community and to the public at large. [Disclaimer, if needed: I am an MIT alumnus. That is, to some extent, why I take the trouble to write this.]

To sum up what I’m about to say, there’s enough blame to go around. Also, the crash investigation failed to look into a number of significant issues or to frame the legal issues accurately. It shows considerable bias toward the truck driver. The Tech‘s reporting missed on a few points. Specifics follow.

The Google satellite view below shows the intersection. The truck was turning the same corner as the tourist “trolley” bus with the green roof shown in the satellite view. This view is from the west, and so north is at the left in the image.

Massachusetts Avenue and Vassar Street, Cambridge, Massachusetts, USA

Massachusetts Avenue and Vassar Street, Cambridge, Massachusetts, USA. Note that north is to the left in this image.

(Cambridge Civic Forum’s blog software won’t let me embed the actual Google view, in which you could scroll around, look from other angles, zoom in and out etc. but you can link to the Google view here.

Now we add Kyaw on his bicycle. He may have been traveling toward Massachusetts Avenue on Vassar Street and stuck the truck head-on, as shown by the arrow coming down diagonally from the upper left in the image below — or traveling toward MIT on the sidewalk of Massachusetts Avenue, as indicated by the arrow at the lower left — or crossing the street from MIT, but not in the crosswalk, as indicated by the arrow pointing straight down from the top. The semitrailer truck crossed the centerline of Vassar Street as it turned. The crash occurred at night, in the rain.

Update: surveillance video excludes Kyaw’s approaching on the sidewalk of Massachusetts Avenue. Damage to the bicycle confirms that it was struck on its left side. Kyaw most probably then was traveling westbound in the eastbound bike lane on Vassar Street and cut across the street in front of the truck.

Massachusetts Avenue and Vassar Street, indicating possible direction of travel of bicycle

Massachusetts Avenue and Vassar Street, indicating possible direction of travel of bicycle

Here is the intersection seen in a Google Street View from the direction of the approaching truck. The three arrows, again, show directions from which Kyaw on his bicycle may have been approaching the intersection. (Update: but not the leftmost arrow in the photo.)

Intersection seen from direction of truck, with arrows indicaing possible approaches of Kyaw on bicycle.

Intersection seen from direction of truck, with arrows indicaing possible approaches of Kyaw on bicycle.

You may also view this Street View in Google Maps.

Here is the Massachusetts State Police diagram showing the final location of the truck, and of Kyaw (to the left of the trailer, on Vassar Street).

Massachusetts State Police diagram

Massachusetts State Police diagram

As also described in the Massachusetts State Police accident reconstruction report, the bicycle contacted the truck’s front bumper and came to rest under the dual tandem left rear wheels of the cab. It evidently was dragged quite a distance farther than Kyaw. The report indicates that Kyaw was not riding in the bicycle lane on Vassar Street (also assuming that he was traveling head-on toward the truck) — but does not indicate that the truck had crossed the centerline of that street. There is similar bias later in the report. As described in The Tech:

“The possible cause of this collision was the encroachment of the bicycle into the path of the turning tractor trailer unit,” the [Massachusetts State Police vehicle accident examination] report [page 6] said.

Encroachment of the bicyclist into the path of the truck when the bicyclist was described as on the right side of the street and the truck partially on the left side? Encroachment means that a vehicle is where it isn’t supposed to be. The bicyclist was encroaching, then?

Different considerations apply if Kyaw was not approaching the truck head-on; I’ll discuss them later.

The reconstruction report goes on to say that

…roadway design and engineering did not precipitate or contribute to this collision.

Nonsense. Though they are not mentioned in any of the reports, a bulbout and street furniture on the corner made the turn difficult for the truck, forcing it across the centerline of Vassar street. The truck driver may have been looking in his right rear side-view mirror to make sure that the rear of the trailer cleared the obstacles.

The Tech goes on to say:

Kyaw’s bicycle’s final position was not in a bicycle lane, the report said. Local laws do not require bicycles to travel in the bicycle lane, and it is common for left-turning bicycles to travel in Vassar’s left lane.

The observation about the law is correct other than that it’s state law, but the last part of the quote is incorrect and misleading. Assuming that Kyaw was traveling along Vassar Street toward the truck, he was in the left-turn lane. Bicyclists must merge out of the bike lane to go straight or turn left without conflict with through and right-turning traffic, or with traffic stopped at the curb. I happen to have a Web page with photos of this very intersection illustrating that point.

Again, however, Kyaw may not have been traveling head-on toward the truck. Then the bike lane is irrelevant, because he then would have been crossing the street, and it is impossible to cross the street while remaining in a bike lane.

The Tech also stated that

The reconstruction report cited contributing factors of “moderate to heavy rainfall,” Kyaw’s nonreflective clothing, Kyaw’s presumed high speed, and the lack of a front light on the bicycle.

A headlight is required by law. The lack of a headlight makes sense as a contributing factor, assuming that the truck driver was looking in Kyaw’s direction, placing some of the responsibility for the crash on Kyaw. Reflective clothing is not required by law. A reflector or reflective material only works if headlights are aimed at it. Rain also may have affected Kyaw’s ability to see. Eyeglasses were found at the scene, and when beaded with rain, they spread glare. Kyaw, like the truck driver, may not have been looking ahead. To merge toward the center of the street, Kyaw should have looked back over his shoulder for overtaking traffic.

The Tech continues:

Kyaw was wearing a helmet at the time of the accident, Cambridge Police report #5 said. The bicycle was “not equipped with a front-facing light,” and its front white reflector was partially obstructed by brake and shifter cables, the report said. Massachusetts law requires bicycles to have a front light at night.

Cables obstructing a reflector don’t seem a likely explanation. They’re too narrow unless the reflector is very small. How the position of the cables could be determined from a bicycle that had gone under a truck also isn’t at all clear. The reflector may, however, have been obstructed by Kyaw’s hand, or its reflective properties compromised by dirt or beads of rainwater. The truck’s headlights were in any case not aimed at Kyaw to light up the reflector as the truck rounded the corner. A large truck’s cab is so high above the headlights that a bicycle’s reflectors barely work if the bicycle is close, see explanation here. A vehicle ahead of Kyaw, or car headlight glare behind him, made worse by a wet or fogged windshield on the truck, may have concealed him.

And, again, if Kyaw was not headed toward the truck head-on, the front reflector is irrelevant.

Kyaw’s 21-speed bicycle appeared to be set at the gear combination that was as hard to pedal in as possible, indicating travel “at a fairly fast pace,” police report #5 said. On the other hand, if Kyaw was intending to turn left and was approaching a red light, it is also possible he was slowing down, or had even come to a stop.

The fifth Cambridge police report includes this statement but also indicates that the shifter for the rear derailleur was in the second-highest position, not the highest.

The discussion of Kyaw’s speed would have benefited from interviews with people who knew his riding style, if they could be found. There are many bicyclists who ride in high gear at a low cadence. On the other hand, he might have been strong and fast, yet still foolish enough to ride at night without a headlight. In this case, he would have been heading into an intersection with a major street against a red light at high speed. I consider that unlikely.

Still, all this brings up the issue of educating bicyclists. I’ve advocated for decades that institutions of higher education provide bicycling instruction to incoming students. Avoiding death or brain injury to even one student every couple of years would more than pay for this. Think of the wasted educational investment, and the loss of future alumni contributions. But I digress.

According to Cambridge Police Report #1, the truck driver “stated that he was traveling westbound on Mass. Ave. when he attempted to take a right turn onto Vassar St. [The driver] said that the light was green and his right directional light was on. Moments later, [he] said he felt the impact of something hitting his truck. He stopped and got out of his truck to investigate and observed that he had been in a collision with a bicycle.

This doesn’t indicate which way the driver was looking — not a very informative statement from him. Did the police ask?

According to the reconstruction report, MIT provided video that showed the truck did activate its right directional signal.

(As indicated in a comment with the article, the video did not show Vassar Street, so it didn’t show Kyaw’s approach).

The police reports say little about the condition of the truck other than that its brakes worked. Was its windshield clean? Were all the mirrors in good working order? Were the headlights aligned? Was the driver’s view ahead obstructed? Etc.

The Massachusetts State Police accident reconstruction report says almost nothing about the bicycle, but page 2 of the fifth Cambridge report describes the locations of scrapes and other damage to the bicycle. These are consistent with the truck’s striking the left side of the bicycle and dragging it on its right side. The front fork was bent to the right, suggesting that the bicycle was struck from the left — except that the front fork and wheel were crushed under the wheels at the rear of the truck’s cab. as shown in the still below from a television news report. I have labeled the locations of the bicycle — the saddle is facing the camera; of a shoe; and of where Kyaw lay following the crash. He had been removed by the time the video was shot.

Locations of bicycle, shoe and Kyaw following crash

Locations of bicycle, shoe and Kyaw following crash

The reports are incomplete in describing the bicycle. Of most importance, what was the condition of the bicycle’s brakes? Even when a bicycle has been damaged by going under a truck, it is possible to examine brake shoe and rim wear, and to determine whether a brake cable had frayed and parted. It is often possible to operate the brakes and determine whether they were in good adjustment.

The bicycle was an under $200 model sold through big-box stores, which are notorious for poor assembly of bicycles — here is the best description of it I could find online. It does have aluminum rims, which brake much better than steel rims in the wet, but how well was the bicycle maintained, and were the brakes working properly at the time of the crash? The police reports say nothing about this.

Though the Massachusetts State Police accident reconstruction report and vehicle inspection report really ought to be definitive on the topics they are supposed to cover, police reports which have not yet been released may possibly fill in some of the missing information.

I hope that my comments have been informative and helpful. — John S. Allen

(Update: please click on the link below to read Paul Schimek’s comments and my replies to them. Paul has suggested that Kyaw was approaching on the Massachusetts Avenue sidewalk. Based on further review of damage to the bicycle, I think that Kyaw may have been cutting the corner from right to left across the path of the truck.)


  1. A seriously biased police report. They need to have a workshop about how to investigate bike crashes. Some day.

    They also exonerated the truck driver with regard to speed, without any evidence. The safe speed for that maneuver was probably 3 mph, not even 10 mph. There is no indication that they even asked for a report on this from the MIT police officer who was apparently standing on the corner at that time(!). Or how about asking the driver how fast he was going? And then recreate the move and check visibility at night given the lighting conditions.

    John, did you consider the possibility that Kyaw might have been riding on the sidewalk and then into the crosswalk, on the wrong side of Mass Ave, Boston-bound? He could still have collided with the front bumper of the truck, fallen, and then got crushed by the trailer wheels.

    The report says that they do not know which direction Kyaw was coming from (no one saw his approach), so there is nothing to rule out the possibility that he was on the sidewalk.

    Based on my knowledge of MIT students, I would say that there is a possibility that typical student cyclists would make a vehicular left turn (trickier after exiting the Vassar side path), but virtually a certainty that they would ride on the sidewalk, at least from time to time.

    Comment by Paul Schimek — May 19, 2012 @ 2:38 pm

  2. Paul — I had assumed that the investigators did know which direction Kyaw was coming from, recalling that the possibility of the truck’s turning right, with Kyaw approaching from its right rear — the classic “right hook” collision — had been discarded early on. Possibly, video from a camera on an MIT building, which showed that the truck’s turn signal was on, also excluded that scenario. Whether that video also would have shown a cyclist approaching on the sidewalk from the far side of Vassar Street, I don’t know.

    I did the String Theory bike ride today in Cambridge and spoke with Robert Winters and Jessica Mink about the crash. Robert asked about the direction of Kyaw’s approach, as you did, and also raised the issue of MIT students’ being more comfortable about riding on sidewalks thanks to the Vassar Street sidepath. Kyaw’s approaching on the Mass. Ave. sidewalk would make for a simpler explanation of why the truck driver did not see him, and why Kyaw did not simply swerve out of the way and avoid the truck: he might have assumed that the truck driver would see and yield to him as to a pedestrian in the crosswalk.

    If Kyaw’s riding on the sidewalk was legal, then the law might say that the truck should yield to him in the crosswalk. The intersection has walk phases concurrent with the green lights for each street. Of course there also is the issue of the difficulty of seeing a bicyclist approaching at bicycle speed, and in the rain without a headlight, compared with that of seeing a pedestrian, and it could be argued that Kyaw darted out into the street too fast for the truck driver to yield to him.

    If, on the other hand, the Bank of America kiosk on the northwest corner defines the sidewalk as being in a business district, Kyaw’s riding on the sidewalk was clearly illegal — though he probably had no way to know that. Whether or not it was legal for him to ride in the crosswalk itself is less clear because the MIT campus, on the other side of Vassar Street, is not a business district.

    Damage to the bicycle and helmet, the location of the dirt from the truck’s bumper on Kyaw’s clothing, clothing fibers left on the truck matched with rips in the clothing etc. might have shown from which direction Kyaw and his bicycle were struck. If some of the physical evidence has been preserved, an answer still might be possible. The investigative reports include some photos, but the quality of their reproduction is poor, and better copies might exist. One of the reports also lists 30 photos shot at the scene. There might be people who knew where Kyaw was coming from and headed to, providing additional evidence.

    In my opinion, a new investigation is warranted, given the plausible alternate explanation and the gaps in the investigation which was done.

    Comment by jsallen — May 19, 2012 @ 9:57 pm

  3. I have responded to readers’ requests to add images to my post. Following this work and another review of the police reports, what stands out is that the bicycle was pushed over onto its right side as it was struck by the truck’s front bumper. This is most consistent with Kyaw’s cutting the corner to switch from wrong-way travel on the northeast side of Vassar Street to right-way travel on the southwest side or turn right onto Massachusetts Avenue. Kyaw’s approaching from a direction where traffic is not expected would make it less likely that the truck driver would notice him.

    Further review of photos and examination of the bicycle might confirm or amend this opinion.

    The difficulty of crossing Vassar Street to reach the sidewalk-level sidepath on the opposite side, when curb cuts are not opposite each other, encourages bicyclists to choose nonstandard routes, and travel wrong-way, as I have described on a Web page elsewhere. The temptation is especially strong for a bicyclist leaving the MIT campus from the Building 39 portal, headed from right to left in the first two images on that page — toward Massachusetts Avenue.

    Comment by jsallen — May 20, 2012 @ 9:07 pm

  4. I could easily spin several other scenarios that might lead to this situation. The one that stands out in my mind given the damage to the bicycle and the conditions, it’s possible that Kyaw panicked and wiped out in front of the truck. Of course it would really help to know where he was coming from. Another possibility in that respect is that he was wrong-way riding, a habit of some inexperienced cyclists in the belief that they can see what’s coming.

    As for the speed of the truck, the video would have made that abundantly clear. And on the gearing, I recall that the report said that the chain was on the smallest cog, even though the lever was not. It’s much more likely that the lever would get shifted in the accident, than that the chain would jump. Or that the big box bike was out of adjustment. At any rate, inexperienced cyclists often use tremendously large gears for every day riding. Knowing more about Kyaws level of ability could also shed some light on what might have happened.

    Comment by Thomas A. Fine — May 21, 2012 @ 10:54 am

  5. Riding in the sidewalk is legal (if you ride at walking speed) everywhere BUT Harvard, Central, Porter, Inman and Kendall (all of which have painted signs to indicate where it is inappropriate at the corners). It technically okay to bike on the sidewalk at the Mass/Vassar intersection and areas.

    Comment by MIT student — May 22, 2012 @ 10:46 pm

  6. The driver does not seem to be at fault at all, beyond the end result. His wide turn was necessary by poor road design changes of MIT and Cambridge executed in 2005/2006 time frame where large trucks need to cross lanes to turn between the two truck routes.

    The cyclist backpack contents and attire suggest he was on route to/from a swimming pool or gym. Where are those located in the area?

    I hope more cyclists learn the importance of visible clothing and legally required front and rear lights.

    I suspect Mr. Kyaw was riding at speed on the Mass Ave sidewalk and made a last instant turn to the right just prior to impact. Vehicle operators do not have right of way on crosswalks or when there is a walk signals. Bicycle riders need to dismount and walk to gain right of way at walk signals.

    Comment by Mark Kaepplein — June 8, 2012 @ 5:00 pm

  7. MIT has a swimming facility at 120 Vassar Street on the opposite side of Mass Ave from the accident. Kyaw’s home was at 284 Harvard St, Cambridge. It seems likely he was headed to the Zesiger pool, given he was wearing workout clothes and dress and swimming clothes in his backpack, along with wallet and iPhone.

    I don’t recall the report mentioning the blindingly bright lighting from the ATM kiosk in the eyes of the driver. Businesses, including Apple, use holes in bylaws to get away with bright lighting and signage to advertise their presence.

    Comment by Mark Kaepplein — June 8, 2012 @ 7:57 pm

  8. My adult son who lives in Brookline Village and works on Athaneum St.and commutes by bike almost every day told me when he heard about this fatal accident that he never rides through the Vassar St./Mass Ave intersection as he thinks it’s too hazardous. He always rides in the street and even on bright sunny days wears a reflective yellow vest, a cut off version in the summer when it’s hot. He also has lights and reflectors. And, as far as I know, obeys the rules of the road.

    As a pedestrian and occasional driver I am appalled and sometimes startled by bicyclists who ride in the street, even after dark, in dark clothing and no lights. How is it that adults don’t realize that they are nearly invisible to drivers? There outta be a law! I even wear a reflective vest when I’m walking in the dark in winter if I’m wearing a dark jacket. Further, the fact that construction workers and police on traffic details always have large reflective jackets is evidence that a human being in the street is always at risk. In the absence of laws, cyclists should be smart enough to try to protect themselves. I don’t mean to suggest that the cyclist killed in this accident was at fault – I have no way to judge that – but no matter what he was not struck by a speeding vehicle running a red light, for example.

    The public responsibility for making the roads safer include more stringent laws about bicycles and their riders – reflective clothing etc, not riding the wrong way, and not assuming a right of way on sidewalks – and enforcement of these laws. Frankly, I think the Cambridge police are too lackadaisical in enforcing road rules to protect pedestrians. I cross the street in Central Sq. several times a day and have never observed a driver being stopped for failure to yield to pedestrians, running yellow/red lights, making illegal turns etc. Better signs would help drivers too – like the ‘no left turn’ signs.

    Comment by Colleen Clark — June 13, 2012 @ 1:28 pm

  9. Thanks for your very well-reasoned statement. I’m with you on this. There is a law. Bicyclists are required to to obey the rules of the road, and to use a headlight and reflectors at night. It’s all in Chapter 85, section 11B of the Mass. General Laws (look it up — it’s online!) The problem is, as you say, that the laws aren’t enforced. They mostly only come into play when fault is being determined following a crash. Then failure to obey the law can be very costly.

    Comment by jsallen — June 13, 2012 @ 2:01 pm

  10. Besides being at night and raining, there wasn’t even moonlight to aid visibility. The new moon was on Dec. 24. The 27th had moon set at 19:52, with only a maximum illumination of 11% at 14:00. Darkness is a major contributor to motorcycle, bicycle and pedestrian accidents, so please be visible!

    Comment by Mark Kaepplein — August 16, 2012 @ 9:38 pm

  11. Your comment sort of reaches for the moon! For one thing, rain falls from clouds, and so the moon would have been obscured. Also, in urban areas, clouds reflect a lot of stray light. There were streetlights in the area, and there was the bright lighting from the Bank of America kiosk on the corner. Without these light sources, the MIT security cameras and the WHDH TV camera couldn’t have recorded their views of the area. All in all, there was enough light to see the road ahead, as is usual in urban areas, and that’s one reason that cyclists make the deadly mistake of thinking they will reliably be seen without having a headlight.

    It would be interesting to know the lighting conditions in the immediate area of the crash. Some light that might have illuminated the cyclist would have been obstructed by the large truck itself; location of streetlights and whether they were operational also would be of interest. But the main issues about lighting are that the cyclist did not have a headlight to render him visible to the trucker; also of concern are the condition of the truck’s headlights and whether the cyclist was where they would illuminate him in the seconds preceding the collision.

    Comment by jsallen — August 17, 2012 @ 9:19 am

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