Monday, May 21, 2012

Pedestrian Delay Measurement at Traffic Signals: A Closer Look

Why don't pedestrian push buttons record how long you have waited? The answer: The engineers haven't set them up to do so.
This past week, we had a visit from a vendor, Campbell Company that has an advanced pedestrian push button that puts a lot more intelligence in the traffic controller cabinet. I think historically the traffic engineering profession has been hesitant to do things like this because of the maintenance requirements, but the device Campbell had and our modern traffic signal controller provides a wide variety of logs that the user can use to determine how well the signal is working for the people that are trying to cross the street. The City of Portland has been measuring delays for pedestrians for almost a year now after developing some basic logic statements in the traffic signal controllers that uses what is already there to produce information we can use. The new push button from Campbell Company seems like a logical next step if they build in the requisite intelligence to make this a reality on more than one level. Here's some text from the report that was written by intern and PSU PhD candidate Sirisha Kothuri (my editorial in italics, emphasis in bold): Along major arterial corridors, (traditional thinking was that) efficient signal timing is geared towards vehicle throughput. Signals along corridors are often coordinated to allow for progression (from one to another on the busier street) and minimize stops and delay for vehicles. While the benefits of signal coordination are accrued by vehicles, pedestrians may be disadvantaged due to higher wait times. The costs and benefits of removing a signal from coordination should be considered and impacts on all users evaluated. Here's the link to the paper and the presentation that can also be found online.
Now what if the signals could tell us exactly when they are going green? Would that reduce people crossing against the signal? The do this currently in Europe.

Thursday, May 17, 2012

Copenhagen Cycletrack Part 2

Just a few more photos from the other side of the street. This particular location didn't have any provisions for left turning cyclists, so a simple Copenhagen hook turn was made at this location. The woman on the right hand side is looking for an opportunity when the signal is green for the side street to cross the busy cycletrack. The second photo in this group shows the bus in the background a little better and the waiting area being used by four passengers.

The notion of sharing space is clearly practices by the Danes at this location every day and it seems to work. Again, the sidewalk is a different texture than the cycletrack and the waiting area. THe second photo also shows poles in the buffer area that are very close to the travel lane. The maintenance staff at the City would frown on that treatment and it is clearly a tradeoff of accessibility of the signal and the visibility of the indication. The second photo shows the waiting area resulting in a wider cycletrack where people on bicycles can pass slower moving people.
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Cycletrack in Copenhagen

I was reflecting on the NE Multnomah project and the cycletracks that were designed as a part of that process. I was trying to recall how the Danish dealt with buses on their cycletracks and this particular intersection came to mind because it was the traffic signal closest to our starting point. From right to left, the corss section is approximately 12 feet for the sidewalk, a 7 ' cycletrack, a 4' buffer to the "curb" lane (which was heavily travelled by buses, and a through vehicle travel lane. The curbs were hardly noticeable and the distinction of the various facilities was met with the changes in texture to some degree. The 4' buffer was cobble stones and bumpy if you were in a wheelchair or on a bicycle. I can't speak to the feel if you were driving, but I imagine it was similar in nature to what you would experience on the Light Rail in dowtown Portland or on NW Marshall in Portland's Pearl District.

The people on bicycles outnumbered the person capacity of the vehicle travel lane as you can see from the massive platoon of cyclists that are using the facility shortly after the a.m. peak hour had died down. There was no weaving between the bus and the people on bicycles, which left the boarding and alighting passengers for the bus in somewhat of a precarious situation, but something that the 4' buffer could address and the bus driver could assist with by alerting alighting passengers of the risk by using the rear view mirrors and warning of approaching conflicts.

Our challenge in Portland with implementation is focused on the accessibility requirements associated with the Americans with Disabilities Act. We haven't solved the issue, but it is something that we need to address so we can move towards separation for people on bicycles which may offer more comfortable conditions.
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Wednesday, May 9, 2012

What Portlanders Want as a City Service?

The Oregonian posted a front page story about what citizens think that we should be spending money on: Portland should fix streets, go after jobs before adding bikeways, streetcars, new poll says I was surprised by the results, so I asked for information on how the questions were worded. The response from the Oregonian is posted here I appreciate that they provided this. Using the term bicycle amenities is a part of a leading question. I have a hard time defining what an amenity is. My simple mind translates that term as something more than what you need, a "Nice to Have". Is an amenity a shower facility? The definition of amenity is: the quality of being pleasant or attractive, Something that contributes to physical or material comfort. My initial reaction as a citizen of Portland when asked to choose maintenance of anything to creating amenities for someone that I don't associate with is going to be negative. The original article should of mentioned that. Just a few thoughts based on a quick google search (why doesn't the Oregonian reporting staff do this?). Is a bike lane an amenity or just a basic service? A bicycle lane doubles as a shoulder on some streets. It increases safety for all users. There's some good estimates of this at the Federal Highway Administration website. This group isn't necessarily known for embellishing the benefits of bicycle infrastructure. Source: Bicycle "amenities" can increase the transportation supply for the system, expanding the capacity to move people. Anyone that visits the approach to the Hawthorne Bridge (during the peak traffic periods) will see a great example of this. The Oregonian's story shows a nice picture of this in the story. Four cyclists in a lane with a bunch of cars and one of the cars even has a bicycle on top of its roof. Bicycle traffic offers the potential to provide increased person movement capacity. People may not want bicycle amenities, but as a motorist, it's likely you're benefiting from the simple fact that there are 6% less cars trying to occupy the same space you are as you drive over the bridge. Source:

Speaking of Beacons

WTS Portland Presents - HAWKS and Beacons: Pedestrian Safety in Portland
Begins: May 10, 2012, 5:30 PM
Maseeh Engineering Building at 1930 SW 4th Avenue ITS Conference Room, # 315 \
Portland, OR 97201 --------------------------------------------------------------------------------

The number of pedestrians killed on Portland streets was 15 in 2010. Mayor Sam Adams reconfirmed his commitment to Vision Zero at the 6th Annual Transportation Safety Summit in March. While the overall safety numbers in Portland have shown a long-term, downward trend, the pedestrian fatalities have remained relatively static. There are a wide variety of treatments that the City is using to make crossings that provide pedestrians safer places to cross. PBOT Signals Division Manager Peter Koonce will describe the use of traffic signals and beacons and the results from studies completed to evaluate the effectiveness of the various treatments. Participants will come away with a greater understanding of why the City is using beacons and the applications where they are being installed. This is a joint WTS-ITE event, member rates apply to a member of either WTS or ITE.