Posted by Jonathan Maus ( Publisher/Editor ) on October 3rd, 2012 at 11:09 am
(Photos © J. Maus/BikePortland)
The Bureau of Transportation (PBOT) activated a bike-only signal yesterday at the northwest intersection of NE Lloyd Blvd and Martin Luther King Jr. Blvd.
The new signal is for people riding bicycles westbound on NE Lloyd Blvd. At this location, MLK Jr. Blvd is one-way only in the southbound direction, so this signal (unlike others PBOT has installed) isn’t to prevent right-hooks. Instead, PBOT is using it to help people on bikes get a head start across the intersection. The reason PBOT invested in what they call a “leading bicycle interval” at this location is because many people merge left over two lanes of traffic in order to ride up onto the path that leads to the Eastbank Esplanade.
PBOT’s Division Manager of Signals, Street Lighting, and ITS (Intelligent Transportation Systems), Peter Koonce wrote about the signal on his blog last night. Here’s how he describes the rationale:
“There is an access to the Eastbank Esplanade to the west of this intersection, so the leading bicycle interval for the eastbound movement allows people on bicycles to get the jump on the vehicle movements and weave across the lanes to turn onto the sidewalk that leads to the path.”
And if you’re curious about how much of a jump bike traffic gets, here’s more from Koonce:
“The length of the green time advance for the bicycle signal is dependent on the eastbound traffic. The bicycle signal westbound is active when the eastbound movement starts and continues when the eastbound vehicles start. Another way to think of this movement is that it mimics the WALK interval for pedestrians on the north crossing of the intersection.”
Koonce says because the signal pole and the required wiring was already there, this cost the City just $2,000 to install.
I watched several cycles of this signal this morning and it gave people on bicycles about an 8-10 second jump on adjacent traffic. When bike traffic was present for start of the green phase, it worked like a charm and they were able to make the merge without having to worry about people in cars slowing down for them. (Note that if you arrive at the end or after the bike green phase, the signal does nothing for you.)
Here are a few more photos…
This isn’t the first time PBOT has installed a “pre-green” for bikes (and it’s their 12th bike-only signal currently in operation). There’s also a leading bicycle interval on NE Broadway at Victoria. PBOT has had bike-only signals installed for many years, but a major bureaucratic hurdle was cleared when the Oregon State Legislature gave them the stamp of approval in 2011.