Dear Dr. Gridlock:

I have recently had several incidents in which I was forced to jam on my brakes to avoid hitting the car in front of me. The driver ahead was braking suddenly because he saw bicyclists on the side of the road at a W&OD Trail intersection waiting for motor vehicle traffic to clear before crossing.

I assume these drivers think themselves kind and considerate when they allow bikers the right of way, but they fail to see the dangerous situation they are creating. When I am forced to stop behind these logic-deprived people I must control my inclination to honk my displeasure, for then I would be the one who appears discourteous.

— J. Kerr, Purcellville

We often discuss situations that pit cyclists against drivers, but this isn’t one of those. The cyclists are doing what they should be doing and waiting for cross traffic to clear so they can move from one trail segment to another.

Drivers, meanwhile, have an obligation to yield to cyclists or pedestrians in a crossing. That sounds simple enough, but drivers and trail users sometimes question the definition of “in.”

I’ve put this to police and other officials concerned about safety, and they generally say that the person should be in the act of crossing, rather than waiting on the sidelines thinking about it.

Kerr is citing a real danger in which a courteous driver sets up a scenario for a rear-end crash. On the other hand, the lead driver might just be confused about the trail users’ intentions. Maybe the braking driver has decided not to risk having two tons of auto collide with flesh and bone.

The W&OD Trail has 70 roadway crossings. That’s a lot of potential for confusion and misunderstanding. The Virginia Department of Transportation has been concerned enough about the danger to experiment with painting zigzag white lines along such roadways to get drivers’ attention, so they’ll be more cautious near trail crossings.

For similar reasons, the National Park Service has been reworking the safety features for points where the Mount Vernon Trail crosses George Washington Memorial Parkway.

Pavement markings and other safety modifications are welcome, but travelers shouldn’t need them. They should always be prepared to protect themselves and others on the roads.

Sounding off

Kerr noted the common temptation to use a car horn to convey displeasure. Another letter writer reflects on the horn’s limited range of emotions.

Dear Dr. Gridlock:

Before the advent of air bags, most motorists were able to moderate horn decibels with the pressure of their thumbs against the horn rings on steering wheels. Alas, with the disappearance of horn rings on newer wheels, enter the one blast for all occasions horn. We can’t choose to be gentle.

Gone is the ability to generate a gentle toot to wake up a napping motorist who didn’t notice the light changed to green, as opposed to the blast that sends a warning of your existence to errant motorists who strayed into your lane.

With the arrival of shifter paddles on each side of some steering wheels, why not add a similar pair of devices on each side of the wheel? One would be a gentle reminder and the other a blast for urgency . . . for love of civility!

— Ernest M. Levy, Clifton

In faulting vehicle technology, Levy is willing to give modern drivers the benefit of the doubt about their behavior with horns. In fact, many of us don’t have much experience tapping car horn pads and can surprise ourselves with our own high-volume response to what we actually considered a low-level annoyance.

Others can take no such refuge in technology. If cars came equipped with hockey horns, they’d use them, too.

Advice from the Maryland driver’s manual: “Sound your horn only to warn a pedestrian or the driver of another vehicle of your presence. The horn is not intended to take the place of brakes.”

Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer’s name and home community. Write Dr. Gridlock at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or