Question: Jim Handy wonders if those buttons you have to push to cross the street downtown are some sort of social experiment.

"My observation and research says they do nothing to speed up or invoke the walk signal, except maybe at night when they are not needed," he says. "Is it just an experiment (as on "Lost," the ABC thriller) to get us to press a button?"

Answer: Wayne Wentz, the Seattle Department of Transportation's traffic management director, said most signals downtown do not have buttons. There are some buttons at intersections on the outskirts of downtown.

He says Handy is right. During the daytime, when there are lots of pedestrians, the buttons don't need to be pushed, and pushing them won't really do anything.

But the buttons aren't some joke by city bureaucrats. He said they're there because at times when there usually aren't many pedestrians, the traffic signals are timed differently and pedestrians have to push the button to let them know they're there.

Wentz also said the buttons only need to be pushed once. Pushing them multiple times won't get you a walk signal any faster.

He didn't say anything, however, about the satisfaction of taking out your frustrations while standing in the rain waiting for the light to change by pounding on the button over and over.

Question: Nancy Ostrander says the left-turn signal for vehicles turning east onto North 45th Street from Stone Way North seems to have gotten really short.

It seemed to be working just fine before.

"However," she says, "using it today it took me three cycles to make the left turn onto 45th, and traffic was backed up into the left-hand through lane.

"The signal was green for about five seconds, long enough to let only two or three cars through (and with some Seattle drivers' slow reaction times, it had already turned yellow before the first car made it into the intersection)."

She wonders if this is just some glitch.

Answer: Wentz said it was a glitch. The sensors that detect vehicles were damaged by nearby construction. They've been repaired now and the signal should be working properly again.

He explains that when the sensors get damaged, "the traffic signal controller has no way to detect if vehicles are waiting for the signal to change; thus, we have to set the signal to run in 'recall' mode, meaning that each approach gets serviced for a set amount of time.

"In general, this interim fix works well, but on occasion it can cause traffic problems such as what you experienced at 45th and Stone."

Wentz said the department doesn't always know when the sensors are damaged, so please let the city know if there's a problem.

Question: Speaking of traffic signals not knowing anyone's waiting, Zev Handel writes in about a recent item on sensors not being able to detect bicycles.

Handel says he stops at three intersections during his brief bike commute from north Wallingford to the University District: at Northeast 47th Street at Roosevelt Avenue Northeast, on Northeast 47th Street at 11th Avenue Northeast, and on 12th Avenue Northeast at Northeast 45th Street.

He says, "It is unclear what the city expects bike riders to do in such a situation. Running a red light, while dangerous and illegal, sometimes looks like the only alternative. But some intersections have so much traffic on the main route (such as Northeast 45th Street) that even this option is precluded. This is an extremely frustrating, and potentially dangerous, situation."

Answer: Wentz says he hears the complaints and the city is committed to improve things for alternative modes of transportation such as bicycling and walking.

Wentz says the department's signal operations staff is evaluating a new standard for detectors that would be more bicycle-friendly.

"That being said," Wentz added, "we do know that there are existing infrastructures in place that are not ideal, even some of the more recently installed. We deal with these on a case-by-case basis. ... There are many variables, and we have some of the best technical staff for dealing with these issues."

He says department electricians will go out to the three locations Handel mentioned to evaluate the detectors.