Susan Sabin reminds listeners of the importance of sharing the road. (Collin Reid/AP)

For amateur cyclist Susan Sabin, the open road is a source of joy and heartache. (Collin Reid/AP)

As a cyclist, I share the road with drivers in vehicles that outweigh me by 3900 pounds or more. If I needed sobering, that alone would do it. But I don’t. My biking buddies and I, retired, responsible adults, try to minimize the dangers by knowing the rules of the road and obeying them. But we love the sport and get together whenever we can. They say it’s good for you.

Until it’s not. Two years ago, at the half point in a group ride, my husband took off alone to get to a meeting while the rest of us finished a leisurely lunch. I never saw him alive again.

Here is what I know about the accident: It was a beautiful spring day with perfect visibility and road conditions. My husband — helmet, bright clothes, pedal reflectors — was riding in the breakdown lane of a straight, country road. The sun was not angling into the driver’s eyes. She came from behind and swerved right, to the side of the road. Although she was not speeding, the impact of her car lifted my husband and smashed him against her windshield with such force that he was catapulted into the air and landed 60 feet away. He arrived at the hospital dead.

Here is what I can’t know for sure, but believe: The driver was not paying attention. She will forever replay the accident in her head, wishing she’d left home three minutes earlier, three minutes later, or noticed my husband three seconds sooner. Her life, like mine, is changed forever.

Drivers don’t want to kill. But they must behave as if a defenseless cyclist is sharing the road with them — because more and more, that is so. Cyclists may test a driver’s patience to the point of frustration; weave in and out of traffic, double up and chat as if in a tea room. No matter. A car wins in any encounter with a bike. Or loses, if it kills.