Signalization: Brian Kemper, SDOT
Kemper took questions from the board in lieu of making a formal presentation.
How does the city weigh vehicles, pedestrians, and bikes in making signal policy?
Seattle has 25 signal electricians and 1000 signals, average for the size of the city. The largest challenge is to satisfy the wide range of users and their conflicting interests. Kemper feels that Seattle does very well in terms of its willingness to install pedestrian-only signals. “Half-signals” are very rare in the US, are not compliant with national standards, and Seattle was asked to remove them. Instead, the city has continued to install them. Combined with mid-block crossings, Seattle has around 100 pedestrian-only signals.
How can we ask for shorter signal length at an intersection, and what are the chances of a request being granted?
For a change to be made, the signal must be malfunctioning, in which case the traffic shop should be contacted at 206.386.1206; or it must be a timing question, in which case Diane Thomas (206.684.5118) or Kemper (206.684.5096) should be contacted. The likelihood of a change being made is more complex, as only 10-15% of Seattle signals are “outlying” or not coordinated with the traffic signal network, unlike in King County, where the signals are not coordinated. It is sometimes possible to look at the whole length of the signal cycle and cut the length in half.
What are the reasons for installing or not installing a pedestrian pushbutton?
Past policy and current policy are very different, and some locations should never have been equipped with pushbuttons in the first place. Currently, pushbutton installation is based on the presence of pedestrians—if any number of pedestrians are regularly seen at that intersection during 75% of the day, no pushbutton is installed. A number of University District pushbuttons will be removed soon, as all the controllers (computers) have been replaced and the entire district must be re-timed.
Some crosswalks are extremely long and the walk time doesn’t always seem to match that reality.
Pedestrian signals are composed of the “walk” and flashing “don’t walk” signals.
Outside of the central business district, the walk signal is only about 5-10 seconds long, and the critical element is the flashing don’t walk, which provides “clearance time” to get pedestrians out of the crosswalk. SDOT assumes a four foot/second walking pace, and from there the clearance time is fine-tuned based on the primary customers of the crosswalk—for example, retirement home residents—and the signal is timed down to a slower pace as necessary. Streets downtown are narrower, so the walk signal is at least twice as long and less clearance time is necessary.
Why is a pushbutton the default, rather than an automatic walk signal?
There are three main signal types: Fixed time, semi-actuated, and fully actuated. Fixed signals are most often seen in the central business district and have no pushbuttons and no vehicle detection. Signalization here is based on historic traffic trends. Semi-actuated signals have no button or detection on the main street, but the minor street has those elements. Seattle has a fair number of these. Fully actuated signals have buttons and detection from all directions, and are rare in Seattle.
Is it normal to have a short walk signal when there is no pushbutton?
Yes—the timing is different for when a signal turns green just for a vehicle; the walk signal will not come up at all and the vehicle light will stay green for only about five seconds, versus about 20 seconds if the pushbutton were pushed.
Is there a policy to make accessible signals the norm?
Kemper suggested that this might be an issue for the board to tackle. Accessible signals are likely addressed in the ADA, and accessible signals will be installed along the entire light rail line along MLK Blvd. The city has purchased 20 accessible signals and is “sprinkling” them in wherever Lighthouse for the Blind and other agencies suggest them. The two downsides to accessible signals are the high cost, which prevents wholesale replacement, and complaints from neighbors about the noise. It is hard to balance everyone’s needs. Kemper said SDOT would really appreciate input on the varied pitch, sound, and vibration options, as a standard has not yet been adopted.
How is the location of “no right turn on red” intersections decided? This could have positive pedestrian impacts.
Unfortunately there are many motorists who don’t seem to care about pedestrians. No turn on red is used very infrequently, and across the US there is an all-or-none approach with it. There must be a demonstrated need in order to change policy, and while motorists may annoy pedestrians turning & cutting them off in the crosswalk, pedestrians are not being killed because of this.
In what cases are protected left turns implemented?
Implementation for the last 15 years has been based on a formula that considers crashes and the numbers of left turning and opposing vehicles. The pedestrian outcome is admittedly not the best, and in general everyone is delayed.
People don’t seem to know what to do at intersections with half-signals.
SDOT has received no complaints about them since the 1980s, and there has been a significant reduction in crashes at all half-signalized intersections.
How much do signals cost?
Full signals are three to four times more expensive than half signals. SDOT is always looking for low-cost solutions, and attempts to reuse the most expensive parts. Half-signals can be installed for $15-25,000. An all-new full signal will cost $150,000.
Kemper requested that SPAB members call or email him with any further questions.
Transportation Budget: Vice
Vice met with Peter Lagerwey of SDOT, David Levinger of Feet First, and Seattle Bicycle Advisory Board chair Emily Allen to review the 2004 budget.
Funding for the adult crossing guard program is currently slated to be cut 50% in 2004 and 100% in 2005. A potential strategy to keep the guards funded is to shift them out of the Police Department and into SDOT, as SDOT analyzes the crossing guard program as it is. Volunteers could also be used if the program was shifted to the schools, but there are negatives to that solution. Council President Steinbrueck is in favor of retaining the program.
This year’s budget process is close to ending, but as stated by Hoyt, pedestrians fared relatively well this time around. However, the 2005 budget will include drastic cuts, and the board must be on top of the process. There has been a lot of talk about pedestrians recently, but there has been no money.
Fellows mentioned that past city improvements have all been funded by bonds, and that some sort of funding mechanism such as bonds, levies, or impact fees should be created for pedestrian projects.
It was suggested that a letter be written to emphasize the board’s demands for pedestrian funding for 2005.