Star-Telegram - Study: Lanes aid cyclists, motorists - 25 September, 2006

Cyclists ride in the bike lane that runs along Trail Lake Boulevard in Fort Worth near Encanto.

Ideally, 5-foot-wide lanes are preferred for bikes, researchers say. Striping city streets with special bike lanes isn’t just safer for bicyclists. It also helps maintain order among automobiles. So says a University of Texas at Austin study released last week. (Read it: www.utexas.edu/opa) Painted lanes make it more clear to motorists just how much room their two-wheeling brethren really need.

“Without a marked bike lane, there appears to be a lot of uncertainty about how much space each person needs, even when adequate road space is provided,” Randy Machemehl, director of UT’s Center for Transportation Research, noted in an online summary. Ideally, 5-foot-wide lanes are preferred for bikes, but even 4-foot lanes are worthwhile in cramped quarters, researchers say.

That’s important because many streets are being retrofit to accommodate bikers, especially as cities try to encourage alternative forms of transportation to comply with federal clean-air rules — and sometimes 4 feet is all the street department has to work with. The study included observation of car-bike interactions mostly in the Austin, Houston and San Antonio areas, according to a UT news release.

Video evidence taken while volunteer cyclists made their way through various towns show that automobiles often veer much farther away from bicycles than necessary. When a bike lane wasn’t striped, motorists often veered into the path of oncoming traffic to make room for bicyclists — unnecessarily.

“You could put a whole car between the bicyclist and them,” research assistant Ian Hallett observed. Even with striped lanes, six of 10 drivers swerved, but they only veered about 40 percent as far as those who weren’t guided by stripes, research shows. The videotaping of “8,000 passing events” between cars and bikes was documented in February and March 2005.

“It took them a long time to look at all that video,” engineering college spokeswoman Becky Rische noted. Another benefit: bicyclists on marked lanes are more likely to obey stop signs and other traffic rules, and less likely to ride on sidewalks — a recipe for danger, because motorists aren’t expecting them there.