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Part I focused on John S. Allen’s analysis of one of the major problems with bike lanes: the increased risk of a car-bike collision at every major intersection, especially road junctions. Allen analyzed a bike lane ending at a “bike box” ahead of the motor vehicle stop bar. This may mitigate car-bike turning collisions at major intersections when the traffic light is red, but doesn’t help otherwise.

This Part II highlights the work of Keri Caffrey.

Keri Caffrey

Keri Caffrey

Keri Caffrey is co-founder (with Mike “Mighk” Wilson) of Cycling Savvy, the most important new bike education program to be introduced in the U.S. since the Effective Cycling program. She is also a competent and visionary on-road cyclist, and a gifted artist and animator, and these skills are apparent in her work. She has produced a convincing animation illustrating the ever-present danger to a cyclist in either a bike lane or riding near the road edge of being hit by a passing motorist turning right across their path, in this case at a traffic light.

Tractor-trailer and bicyclist positioning at major intersection

Tractor-trailer and bicyclist positioning at major intersection

This still image by Keri Caffrey is based on her on-line animation at “Why Bike Boxes Don’t Prevent Right-hooks

It illustrates clearly the danger of being to the right of a tractor-trailer at a major intersection at which the motorist may turn right across the cyclist’s path. The cyclist is in the motorist’s blind spot, in which he is unable to see external objects directly or in his right-hand mirror. The cyclist, meanwhile, has no inkling of the driver’s intention to turn right.

Keri Caffrey has also produced a great animation contrasting a bicyclist exercising lane control with edge riding (comparable to riding in a bike lane). It is posted at “Lane Control” from which the following still images have been captured for the edge riding cyclist.

Numerous potential hazards encountered by an edge (or bike lane) riding cyclist are shown in the first slide, including Close Passing, Pavement Hazard Area, Moving Screen as the passing car hides the cyclist from view, and Intersection Conflicts (which also applies to every driveway, especially commercial driveways).

Please mouse click on any of the following images to enlarge. Use the back button to return to this page.

General edge riding safety issues

General edge riding safety issues
Click to enlarge this or any following graphic. Use back button to return to this page.

Edge riding cyclist was hidden from oncoming left-turning motorist by passing green car.

Edge riding cyclist was hidden from oncoming left-turning motorist
by passing green car (at right and alongside in previous graphic).

In-lane passing by utility truck taps edge riding cyclist.

Edge riding cyclist is prevented from avoiding road debris.

Motorist passes cyclist just before making a right turn.

Motorist passes edge riding cyclist just before making a right turn.

Drive-out conflict due to screening by turning motorist and/or vegetation.

Drive-out conflict due to screening by turning motorist and/or vegetation.

Part III, the last blog in this series, is a critique of a list posted on-line titled “21 Good Reasons to Mark Bike Lanes.”

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