WTS Speaking Engagement

WTS November Luncheon Featuring Peter Koonce, Portland Bureau of Transportation's New Signals and Street Lighting Manager 
Tuesday November 9, 2010, 11:30 AM - Save the Date

Luncheon Presentation at The Governor Hotel

Today, most streets are designed and managed to meet mobility standards that focus on the movement of motor vehicles, failing to adequately accommodate and prioritize transit, walking, and biking. A new culture of innovation is needed in transportation as traditional solutions alone will not suffice. By 2035, the Portland Plan envisions transportation facilities that are designed and managed to prioritize travel investments that improve walking, biking, and universal accessibility as the first priority.

In support of this vision, Peter Koonce, Manager of the City's Signals, Street Lighting, & ITS Division will discuss how he's looking to make the City's traffic signals consistent with these goals resulting in more effective integration of land use, transit, cycling, and walking.

Please RSVP for this event by Registering Here

Madsen Bucket Bikes

Very cool contest from Madsen. I went to the Bike Gallery unveiling of these things and wanted one back then! MADSEN Cargo Bikes 

WTS Speaker - November 9th

I was honored when I got the phone call to talk about the City's signals during the upcoming Women in Transportation Seminar speaker series. It will be a good time to reflect on the first year at the City and share my vision for how traffic signals should be part of the solution. So much of it is your approach to traffic and following the policies of the transportation plan. Ours is at:http://www.portlandonline.com/portlandplan/index.cfm?c=51314&a=297202

Baltimore City Response to Citizen Inquiry

I came across this letter from the City of Baltimore via Twitter. The City signals staff that I worked with (the transit agency was my client mostly), was pretty focused on moving cars. So, back then, I wouldn't have expected the mention of transit in a response about signal timing. It was a pleasant surprise, or is it greenwashing.

First on Fox...

Following the lead of KATU, Fox interviewed a cyclist for a sound bite.

"I haven't had as many close calls as I used to," said Jeff Ihle, a cyclist. "This was a really bad intersection before because the cars would cross ahead of the bikers and they wouldn’t look. So, this way, it’s just getting used to the new signal. I think it will be OK"

Are No Turn on Red Signs Confusing?

Yesterday, KATU Channel 2 lead off with this as their top story for 4 PM. I don't agree that it warrants front page cover and the news anchor seemed to spin the information a bit. I hope the thing that the citizens of Portland realize is that it is a construction zone. BikePortland.org mentioned it wasn't ready for prime time and that was somewhat true, but at the same time, how many signals are the day after construction while there is still construction active. We seem to be under the microscope a bit for this and I am okay with that, but the video here confirms that often times the public is quick to make an excuse when in reality you're on shaky ground. The cyclists that didn't see the indication... really? There are two locations where we show you the same indication. I am not sure you could miss it AND the two or three signs in advance of the intersection that describe "bike signal ahead".

http://www.youtube.com/watch?v=oesPzCDB4cc&feature=player_embedded

The key to this for drivers is paying attention to the No Turn on Red Sign. That shouldn't be that hard because there are two of them. One that is a static full time sign (the standard black lettering on white) and the other that is dynamic that comes up right before the bike signal is green and then turns off when the right turn is allowed.

When it says No Turn on Red, we're not just offering this as a hmm, maybe you shouldn't do this. It is a requirement.

Signal Timing Using Quarter Cycle Offsets in Downtown Portland

I was interviewed last week for this article by Peter Korn of the Portland Tribune. This blog post is inspried by my attempt to describe the signal timing in downtown without any technical terms to a member of the media. I was sure I struggled mightily and the first time I said quarter cycle offsets, I expected his eyes to roll, but we drew up a sketch discussed the math and related that to his experience. The sketch looked an awful lot like what I had previously written for the Signal Timing Manual back in 2008 while working for the FHWA. Here's the text:

A similar method of manual coordination timing can be applied to downtown grid networks. This method has been deployed in downtown Portland, Oregon by separating intersections into a quarter cycle offset pattern. The block spacing in downtown Portland is fairly uniform and relatively short (280 feet) and the grid is a one-way network. Each subsequent intersection is offset by a quarter of the cycle length, which is selected to progress traffic in both directions. The result is a progression speed that is dependent upon the cycle length. This approach establishes a relationship in both directions of the grid and permits progression between each intersection in each direction based on the speed that is a result of the selected cycle length and the block spacing. As shown in Figure 6-18 cross coordination throughout the grid is achieved using the quarter cycle offset method. This approach can be adjusted to account for turning movements within the grid and subtle  modifications to the distribution of green time.

In downtown Portland, the p.m. peak hour cycle length is 60 seconds, which results in a 15 second time difference between subsequent intersections. To travel the 280 feet in 15 seconds, one must travel (280'/15sec) or 18.67 feet per second or 13 miles per hour. The lower the cycle length, the faster the travel speed. Thus, Downtown Portland has progression in multiple directions at a slow speed which is especially good for buses that are accelerating from a stop, cars that can drive through at a consistent speed and come to a quick stop if someone in front of them pulls out of a driveway unexpectedly, and reasonable for people travelling on bicycles to use the lane and move along the signals without stopping every 280 feet. The short cycle length is also important in the condition that you have a high percentage of turning traffic that can result in queue spillback between the intersections. Short cycle lengths give an opportunity to keep traffic moving. There's a longer debate on short cycle lengths, but the important element of block spacing is a big part of that  debate.

NOTE: for some reason this figure is not available on the FHWA version of the Signal Timing Manual. I have confirmed that this link has a proper copy of the graphic.