Common Hazards: The “Screened Left Cross”

The “left cross” is another common crash type. It happens to both bicyclists and motorcyclists. This can also be divided into 2 basic circumstances. The first happens when a driver simply does not see a cyclist or motorcyclist who is plainly visible. The best way to prevent this is to ride prominently, seek some indication that the driver sees you and keep your pedals moving while covering the brakes with a plan for evasive action in case they violate your right-of-way.

The second type—the screened left cross—is very common in urban riding. It’s something many cyclists (and motorists) are not aware of. It happens when a vehicle is screened by a same-direction vehicle to its left. A motorist turns left in front of or behind the vehicle he sees and hits the one he doesn’t see.

You can prevent this by staying alert to your environment and recognizing where and how this dynamic develops. If you are approaching a queue of traffic, move to the left side of the lane and align yourself so you can see down the left side of the cars in front of you. This way, you can see vehicles waiting to turn left and those drivers can see you.

If you are passing a queue of traffic on the right, move slowly. Recognize that every single gap in that queue that is aligned with a driveway or intersection is an opportunity for a driver to turn left across your path without seeing you.

Be mindful that even when you are controlling a lane on a multi-lane road, traffic passing to your left can screen you from left-turning drivers. The closer the speed differential, the longer you will be hidden, making the lane appear empty. Drivers are typically more cautious about crossing full traffic lanes than bike lanes, but it’s important to be aware of the left-cross potential on any road.

Also, be aware that if the sun is at your back, it is in the eyes of left-turning drivers.

Bike Lanes: An urban bike lane encourages (and, in some states, requires) bicyclists to be in the exact position that makes them most vulnerable to a screened left cross (and numerous other crashes). Never be lulled into a false sense of security. Your risk of being hit is greater when you are beside the flow of traffic because you are in the cross-flow of traffic entering and leaving the road.