Still, the maneuver often catches other motorists off guard. When they see a vehicle moving to the left, the natural expectation is that it’s going to turn left. Drivers and bicyclists think they can pass the truck on the right, only to be surprised when the truck swings right and cuts directly in front of them.
Truck drivers are well aware of this danger. The state’s Commercial Driver’s License Manual tells truckers that they should try to block all lanes of traffic as they swing to the left to make it physically impossible for anyone to pass them on the right. (The next time you’re cut off like this by a trucker, remember, they’re actually doing it for your own good.)
Bike lanes, however, are a big loophole. Even when a trucker or bus driver dutifully blocks all motor vehicle travel lanes, a bike lane remains open. And truck drivers often can’t see a bike lane because their side-view mirrors become significantly angled while turning.
“You’ve seen the signs on the back of trucks — if you can’t see my mirrors, I can’t see you,” said Boyd Stephenson of the American Trucking Associations.
“Like with passenger cars, there is a blind spot. But unlike passenger cars, you don’t have the ability to look over your shoulder to see what’s coming,’’ he said.
Stidman said that some cities, such as London, are experimenting with mirrors on street poles to help truckers see bike lanes. Watson, of MassBike, says his organization has been training MBTA bus drivers about bicycle safety since 2010.
He’d like to expand the training to all commercial drivers in the state, but even if that happens, bicyclists always need to be aware of large, turning vehicles whose drivers might not see them.
On that note, Watson, Stidman, and Fitzgerald offer the same advice: Whenever you bike alongside a large vehicle, assume it’s going to turn in front of you at the next intersection, and slow down.