Have you ever been standing on the side of the road and had a car go by you at 50 mph just a foot from your body or head? It is a scary experience. It happens to me several times per year, but not when I am standing on the side of the road.

It happens when I am riding my bike.

By state law, that shouldn’t happen.

Five years ago the Legislature passed a law to make Maine roads safer for bicyclists and roller skiers. It is the 3-foot rule (Title 29-A, Chapter 19 (1), Section 2070) and it states that a motorist must come no closer than 3 feet when passing a bicyclist or roller skier.

That is common sense and common courtesy.

Most of us instinctively stay more than 3 feet from a cyclist. But some do not, thereby breaking this little-known law. Cyclists need to inform the public. The police need to inform violators, but they cannot do it without cyclists’ help.

A surprising number of drivers feel they have the right to continue going at speed despite the presence of a cyclist in the road and under dangerous conditions. They pass the cyclist when there is a car coming the other way. The result is three vehicles pinched into a space wide enough only for two, with the cyclist and probably the oncoming driver feeling threatened.

The pavement of the travel lanes of most roads in Maine, including the road in the picture that accompanies this column, is 11.5 feet. A vehicle — with rear view mirrors — measures 7 or more feet wide. Add 3 feet to satisfy the law and only 1.5 feet remain for a bicyclist, nowhere near enough.

A bicycle is about 2 feet wide, and often needs to travel at least 3 feet from the edge of the road to avoid potholes, cracks and other obstacles that would not bother a car. Total footage needed for a safe pass equals 14 feet. Thus, it is illegal to pass a bicycle without going well over the center line.

In the accompanying picture, the passing truck is a foot over the center line even when the bicycle is dangerously close to the shoulder and the truck is the minimum 3 feet from the bicycle.

I have been biking in Maine for 30 years. I am fortunate to live where I can bike on rural roads with few cars. I typically encounter only about 100 cars during a ride.

Most drivers are very considerate, going all the way into the opposite lane to pass me. But once or twice per season I get “buzzed” by a driver who is uninformed, reckless, rude, or all three. For those occasions I have developed a quick reflex to see and memorize the vehicle’s license number. I report the driver to the police as soon as I can. The police are very receptive to my calls. They contact drivers to inform them of the law.

Sgt. Gary Boulet, public safety officer of the Auburn Police Department, recommends that bicyclists hone their license grabbing reflexes. You have only a few seconds in which to do it, so you must maintain your cool and focus quickly. Try also to note the make and color of the vehicle. That information will help if you did not get the license number perfectly.

The police are sympathetic to your plight, but they cannot do much if you do not give them a license number.

The 3-foot rule can make Maine a safe and pleasant place for biking, but it needs the public’s help. With the Dempsey Challenge coming up (Oct. 13-14), we want all those visiting cyclists to think that Lewiston-Auburn and Central Maine are great places to ride.

Drivers need to be considerate and law-abiding, and not just on Dempsey Day.

Ben Lounsbury of Auburn is a doctor and amateur athlete who is trying to age gracefully, not all at once. He is a member of the Maine Cycling Club.