Here's a rundown on the responsibilities of bicyclists under Virginia law, and common-sense advice:

Ride in the direction of traffic. "That's always one of the big issues in terms of contributing to crashes, wrong-way riding against traffic," VDOT's Jakob Helmboldt said.

Stay right. "The law basically says that a cyclist should ride as far to the right as practicable," he said.

But staying to the right does not mean a bicyclist must leave the road. "You don't want to be so far to the right that you are risking riding in debris or riding off the edge of the pavement," Helmboldt said.

In an urban environment, ride 2 or 3 feet away from parked cars. Someone could open a car door suddenly, creating a vertical steel hazard. "That's the most dangerous place you could be," said Elizabeth Kiker, League of American Bicyclists spokeswoman.

When biking on a narrow road, with lanes less than 12 feet wide, cyclists are allowed to take the full traffic lane. Also, if bicyclists are traveling at the speed of traffic, they may use the full lane, said Elizabeth Kiker of the League of American Bicyclists.

Obey stop signs and traffic signals.

Be as predictable as possible, biking in a straight line, Jakob Helmboldt of the Virginia Department of Transportation advised. Do not weave in and out of empty parking spaces on the side of the road.

Bicyclists are allowed to ride two abreast under state law, as long as they do not impede traffic. However, the Department of Motor Vehicles encourages bicyclists to ride single file.

Use hand signals, but don't count on drivers to understand them. Make eye contact with drivers to ensure they know you are turning. "Turn around and say: 'Do you see me? Do you see I'm going to merge?' Pointing helps with that," said Kiker, who bikes to her office in Washington.

Be in the proper lane. If turning left, be in the left turn lane. Turning right? Be in the right turn lane.

Not ready to navigate an intersection? Dismount and cross as a pedestrian. Bicyclists are allowed to ride on sidewalks, unless a locality has an ordinance prohibiting it. Once on the sidewalk, bicyclists are pedestrians.

Wear a helmet. There is no law requiring anyone 15 or older to wear a bicycle helmet in Virginia, but it's a good idea, Helmboldt said.

Motorists have a responsibility to keep bicyclists safe, too. "You're behind the wheel of a vehicle that can create instant carnage," VDOT's Jakob Helmboldt said.

Virginia law requires motorists to pass at least 2 feet to the left of a cyclist at a safe speed. The League of Ameri-can Bicyclists recommends leaving a 4-foot buffer.

When you see a cyclist, slow down and pay attention. Do not change the radio or answer a cell phone.

Drivers should wait for a safe gap in traffic to move around a cyclist, Helmboldt said, as they would when they pass a vehicle.

If traffic lanes are narrow, motorists may need to encroach on the adjacent traffic lane to pass, keeping the 2-foot buffer.

Be familiar with your vehicle's width, and know how far you need to move to the left to keep the minimum 2-foot buffer.

Do not tailgate a bicyclist, because debris in the road may force the bicyclist to move suddenly.

Do not try to beat a bicyclist to an intersection, especially when you are making a right turn.

You may misjudge the speed of the bicyclist, running into him as you turn, a crash bicyclists call getting "right hooked." Let the bicyclist pass through the intersection first.

Try to appreciate bicyclists. Each cyclist takes another car off the road, VDOT's Jakob Helmboldt said, and improves air quality.

Why don't they build more bike lanes in the Fredericksburg area?

Competing priorities are a challenge to building bike trails, said Andy Waple, senior regional planner at the George Washington Regional Commission in Fredericksburg.

Waple organized a survey of 428 area bicyclists last year. He found safety concerns and a lack of off-road trails kept residents from biking as often as they would like.

Plans are in the works for more area trails. For more about them, see A6.

VDOT and the DMV record bicyclist fatalities each year:

2007: 7

2006: 12

2005: 20

2004: 9

2003: 9

2002: 8

There were more than 850 bicycle-vehicle collisions with injuries in Virginia in 2006. VDOT's Jakob Helmboldt said that number is underreported.