Q: What's with those bright white lights blinking on buses inside the downtown bus tunnel? Seattle resident Henry Szymonik, who has returned to the renovated and reopened bus tunnel, says they seem like overkill.

Metro Transit says those lights, strobes attached to the side-view mirrors of buses, are a warning for waiting passengers in the tunnel to stay back from the curb, behind the yellow stripe, so they won't be hit by the mirror of an approaching bus. That's a safety concern because the tunnel floor has been lowered eight inches, so the boarding platforms will match the height of a new generation of low-floor buses and future light rail trains. But the lowering also brings the mirrors down to head levels.

Szymonik thinks those strobes are too white, and too bright. "Why do the new lights need to be so bright, and why do they need to flash so rapidly?" he asked. "Having to see those bright, rapidly flashing lights as I was watching for my bus hurt my eyes," he said. "I actually kept seeing lights an hour later."

It seems, he said, that low-level red LED lights would be sufficient to accent the side mirrors, and would provide better contrast to the bright white headlights.

A: The reason the strobe lights on the side mirrors are so white and so bright is so they will be highly visible to passengers waiting on the platform inside the tunnel, says Mike Lemeshko, supervisor of Metro's transit safety unit.

The strobes are an extra safety measure to make sure customers are aware of the position of the mirrors as the buses move along the platform. Metro spokeswoman Linda Thielke said the agency wanted to make sure that passengers who might have their backs to the platform and the moving buses would be aware of the mirrors, and that is why the lights flash.

It's true. Someone could be injured if struck by a mirror. "But there's that potential at any other bus stop, too, depending on your height," Lemeshko said.
Yellow safety stripes intended to keep people away from the curb have been used in other places, he said. The speed limit for buses as they approach and leave tunnel stations has been lowered from 15 mph to 10 mph. That way, drivers should be able to honk their horns and stop the bus if necessary, Lemeshko said.

The mirror lights are set at low strobe, between one and three flashes per second, "and they shouldn't blind anybody," he said. When buses stop, the strobe goes off automatically. Then it restarts automatically when the coach doors are closed and the bus reaches 15 mph.

Metro had considered using amber lights, Lemeshko said, "but we found that they blended with other marker lights on the buses." The agency wants the mirror lights to stand out, and doesn't figure the solid headlights and flashing mirror strobes should be confusing.

"We're evaluating it as we go along to see how effective it is," he said. "It's a work in progress." But so far, there are no plans to change the lights.