ACHD's Road Wizard Sunday, August 27, 2017

The pedestrian signal was checked and is working as programmed. But how the signal is programed may make it seem like the signal isn't working.

Sometimes in coordinated traffic signal systems, pedestrian "walk" signals are displayed automatically when drivers traveling in the same direction get a green light. However, the green light has to be consistently long enough to provide time for crosswalk users to make it across the street.

The green lights serving Pine drivers aren't that long since it's a side street with comparatively little traffic. There isn't enough time to automatically display a walk signal for pedestrians crossing Eagle Road. A pedestrian needs to push the walk button to tell the signal to add in the time for a crosswalk user.

Things may seem off if the button is pressed just before traffic gets a green light. The signal may have already checked for a pedestrian, found no one waiting, and moved on. Since the pedestrian signals are shown during the green lights for parallel traffic, a pedestrian then has to wait through the whole signal cycle.

The signal cycle at Pine and Eagle can last three and a half minutes, which can make a pedestrian feel ignored. Or the system may appear broken because the crosswalk signals for people crossing Pine do automatically activate. The green lights on Eagle match up with the required crosswalk time.

Pedestrians may show their frustration by pushing the walk button over and over, expecting the signal to activate right away. But pedestrian signals have to be incorporated into vehicle signal timing plans to maintain traffic flow.

The Manual of Uniform Traffic Control Devices sets the standard for street line paint nationwide. It says that centerline striping should be placed on rural roads with greater than 3,000 vehicle trips a day. For the sides of a road to have a line, the number should reach at least that same number.

The last traffic counts on Homer showed about 160 vehicles a day east of Park, and 220 vehicles east of nearby Ballantyne Lane. Beacon Light has much more traffic, so it gets the stripes.

There is room for "engineering judgment" in making decisions about street markings, but foggy conditions alone generally don't warrant street paint. In fact, over the last 20 years, only one crash was reported on Homer that mentioned foggy weather. Homer is a bit hilly, but not enough to justify street paint.

This is a case where traffic engineers must differentiate between wants and needs. There is a tendency to think that adding bigger, brighter traffic control markings and devices automatically results in safer roads, but it can be a tough sell for low volume streets.