OC Transpo driver in fatal bus crash lost steering, expert testifies
Defence expert says driver tried unsuccessfully to turn left and out from gutter curb
The driver in the Westboro bus crash trial tried unsuccessfully to turn left and out from the gutter curb leading up to the Transitway station before the double-decker continued on its course, a collision expert called by the defence told court Tuesday.
The Jan. 11, 2019 collision injured at least 35 people and killed three — Judy Booth, Anja Van Beek and Bruce Thomlinson.
Diallo, 44, has pleaded not guilty to all dangerous driving charges against her, including three counts of dangerous driving causing death.
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Richard Lamoureux, a collision reconstruction expert from DFA Engineering Services Inc., presented his report to court Tuesday, deconstructing the incident as four collisions, not one.
Lamoureux said his report was based on a combination of video from the bus, data that was downloaded from the bus by investigators and police reports. He said he did not interview Diallo.
Court was shown video from the back of the bus that showed a stop request sign was lit at 3:49 p.m., a little more than a minute before the crash.
Lamoureux said the double-decker's movement was gradual and resembled a lane change to do a stop at Westboro station.
However, he said the sun's glare illuminated an old construction lane marking and may have been confusing to the driver, directing her closer to the snow-and-ice-filled gutter curb leading up to the Transitway.
He said video of the bus's front door, taken from above the driver's compartment, showed a shadow rising on the lower part of a passenger's Canada Goose coat sleeve. He said that shadow movement was consistent with a right arm turning a steering wheel to the left.
Warning: some viewers may find the following video disturbing
Lamoureux said that may have been Diallo's attempt to regain the road way, but the video showed the bus continued moving rightward and Diallo is heard saying "oh my god."
"It's at this point that the bus is out of control," Lamoureux said. "It's not responding to steering."
He said the bus was undergoing "slip," a type of skid where the movement of the bus doesn't match the angle of the wheels. But he said any tread marks that might have indicated the steering change were obscured by the rear wheel tracks, snow disrupted by the collision and an emergency vehicle that parked on the shoulder after the crash.
He said the handling of the fully-loaded double-decker bus, which court has heard was carrying at least 85 passengers, may have been affected by travelling with wheels in the gutter.
Lamoureux acknowledged there were no signs of mechanical defects with the steering, as court had previously heard.
Warning: some viewers may find the following video disturbing
Lamoureux said 0.8 seconds after the failed steering manoeuvre the bus hit a snowbank, 1.4 seconds later it hit the rock wall of the Transitway — shattering its front door and spraying snow into the bus — and about 0.5 seconds after that it hit a second snow bank.
Only 1.9 seconds after that, the bus hit the shelter overhang and came to a stop, he said.
Lamoureux testified that research suggests perception-response time is about 1.5 to two seconds, with about 85 percent of people able to process and react to a straightforward situation in about 1.5 seconds.
"What we have is a series of collisions occurring so quickly between them that a driver doesn't have time to perceive, respond and react to that hazard before facing a different hazard," he said.
Questioning the Transitway design
Lamoureux said the gutter curb on the Transitway doesn't adhere to the Ministry of Transportation of Ontario guidelines for a "recovery area" or shoulder before the curb typically required on a high speed road.
However, Lamoureux noted the Transitway is a private road that doesn't fall under the Highway Traffic Act and the section where the collision occurred had a posted speed of 50 km/h, so it wasn't high speed.
He also said the conflicting road markings from the construction detour, which were left over from a time the gutter had been filled in to allow buses to past, should've been obliterated according to the Manual of Uniform Traffic Control Devices for Ontario.
The markings had been covered in black paint that wore off, court heard.
However, he said because the Transitway is a private road, he couldn't be certain those rules applied in this case.
He said research suggests the sun's glare on that January afternoon would've hampered the driver's ability to detect hazards.
He said when the detour lane marking was illuminated by the sun, it could've been mistaken for the lane marking signifying the widening of the Transitway to two lanes at Westboro station.
Lamoureux's testimony in the judge-alone trial at the Ontario Court of Justice in Ottawa is expected to continue over video call on Thursday.