To Lead or be Exclusive... for Pedestrians at a Traffic Signal

 A fellow APBP member asked the following question: a topic that keeps coming up is the idea of using exclusive pedestrian phases versus other measures to improve pedestrian safety.  I've seen mixed messages on this as an outcome, including the possibility that exclusive phases may have fewer, but more serious collisions, or that pedestrians won't wait for the phase to come up, or that it might not be significant relative to LPI's blank out signage, etc.  On the other hand, it is a relatively simple thing to implement assuming it doesn't result in operational challenges for other modes (admittedly a large assumption in many cases).

Is there anything definitive available for documentation, or at least something that helps with a decision-making process?

My answer:

This is a topic that I have been fortunate to have reviewed a good amount of work from some really smart researchers. Sirisha Kothuri or Portland State, David Hurwitz of Oregon State, Ed Smaglik of Northern Arizona University to name a few. These folks have collaborated on this topic for awhile, but the conclusions on efficiency are pretty similar in every study. Generally, the efficiency from a multimodal perspective is better with LPIs as compared to Exclusive Pedestrian Phasing. The safety issues are much more site dependent and in my opinion difficult to assess. 

Efficiency

Improving Walkability Through Control Strategies at Signalized Intersections by Kothuri, et al

Shorter version in the ITE Journal here 

"The results of the simulations show that the addition of an exclusive pedestrian phase significantly increased delay across the modes when compared to the base case for all pedestrian volume scenarios. These results are intuitive as the addition of an exclusive pedestrian phase increases cycle length, which results in increased delay for all modes."

The Oregon DOT has a nice write up summarizing literature review on LPIs here and Peter Furth of Northeastern University has also done some wonderful research on this topic.

Safety

Of course, delay for all modes isn't the only metric one would consider as you pointed out. FHWA cites the potential for reduced crashes for both strategies as an LPI as 0.413 and that of an Exclusive Ped Phase as 0.49, meaning that there is (1-0.49) 51% reduction in pedestrian crashes is expected for this countermeasure in the Toolbox of Pedestrian Countermeasures and Their Potential Effectiveness

A study of pedestrian compliance with traffic signals for exclusive and concurrent phasing by Ivan, John etal 

"We found that pedestrian compliance is significantly higher at intersections with concurrent pedestrian phasing than at those with exclusive pedestrian phasing, but this difference is not significant when compliance at exclusive phase intersections is evaluated as if it had concurrent phasing. This suggests that pedestrians treat exclusive phase intersections as though they have concurrent phasing, rendering the safety benefits of exclusive pedestrian phasing elusive." 

The paper goes on... 

"This is very important since, as Abrams and Smith (1977) pointed out back in 1977, the safety benefit of exclusive pedestrian phases over concurrent pedestrian phases depends entirely on pedestrian compliance." 

I would caution you about the perspective that it is "relatively simple thing to implement" given potential legal liabilities of accessibility issues at a signalized intersection. This case in Chicago was one that is worth learning more about. 

Response to: Traffic Engineers Are Wasting Trillions and what we need to do about it

 

Traffic Engineers Are Wasting Trillions and what we need to do about it

My initial response to this article was: where in the world have I put my last $1,000,000,000? 

Streetsblog clearly took some liberty with the original video titled: You’ve Been Lied To About Roads For 60 Years, which was published by the Global Cycling Network. Full disclosure, I watch most of the videos that GCN puts on as someone that likes to ride my bike.

This being said, I found myself defending the criticism and the industry on the E-Community of ITE when a fellow member said induced demand wasn't real. Here's the post and the follow up. 

As a lifelong Portlandite, I was surprised to see my hometown enter the discussion. Portland (and Oregon) has had a history of thinking about the land use and transportation systems differently. Every city has an urban growth boundary due to legislation in the 1970s which requires planning of land use and transportation and Portland has sought to provide choices that lead to sustainable solutions that grow community and make a livable place. Ever since the 1972 Downtown Plan, where Housing was emphasized as a transportation solution, the City has been thoughtful about how pedestrian and transit connections are made in context with other decisions. It's not for everyone, but 50 years later, we're still focusing on making the most of existing streets, working toward a community that delivers a safe place to move for all ages and abilities.  

Induced demand is not a myth but I also think there is overstatement of the concepts. We have had steady growth in the Portland region and yet the increase in congestion has been managed by the provision of a multimodal network. The lack of freeway construction and arterial widenings has lead to people finding the inner city neighborhoods to live. Thus, the commute times stay consistently below the national average. People choose to live in Portland because of the quality of the public schools, strong level of investment in the City, and the richness of character with the closer in neighborhoods. Overall, the City has done very well in making multimodal options effective (in my opinion). We have spent a lot of time focusing on intersection improvements for walking, biking, and transit. We have invested in a networks centered around transportation options. The lack of a "drive until you qualify" for a cheaper home loan is worthy of further examination. There is broad recognition that our land use planning has slowed the rate of growth and resulted in an increase in other problems (houselessness, affordability), but that's not my area of expertise. The efforts to address transportation needs with multimodal solutions leads to a high quality of life and public health. People have traded longer commutes for reinvestment in the City and more active forms of getting themselves around. 

I agree that the density of land use and the extent of land development that primarily determines the number of trips generated onto the roadway network. Yet, I would offer that the role of engineers does not stop with solving the congestion issue with one more lane of traffic. We can offer leadership and propose solutions that match the local policies. We should identify opportunities where possible to inform and educate decisionmakers where we have built the trust and relationships as trusted advisors. If we haven't built those relationships, it is up to us to call on colleagues that can help us do that. One person's definition of quality of life is different than the next and that's something that leaders recognize. 

I am also hoping we can uplevel our conversations on this platform.  For someone that can't drive, cities can be wonderful places for those with age or mobility challenges associated with visual or physical limitations. That includes kids, elderly, or people that choose not to drive. As a kid growing up in Portland, I had a lot of freedom provided by the bus or by walking to the neighborhood park. 

Congestion relief may result in longer term problems such as poor safety, fewer mobility options that seem like a reasonable choice, and impacts to the adjacent residents. The freeway construction era had a lot of negative consequences and the days of suburban car-centric focused transportation solutions have lead to the transportation safety crisis that we are faced with today. I completely agree that congestion relief should not be the only goal. 

I am not fond of the criticisms our profession gets from various blogs on this topic Are Traffic Engineers Sociopaths?, Traffic engineers do not share your values, A Traffic Engineer Hits Back at His Profession, and am proud of the work that ITE is doing to change the narrative. Let's keep working to do our part to induce a new story other than engineers only want to widen roadways, so I can go back to watching Global Cycling Network for the bike racing coverage. 

I got brought back to this discussion after I was paid a few nice comments, so I continued with.... 

 after listening to this month's ITE Podcast related to Seville, Spain's experience related to transformative change by implementing a bike network, I will offer that we as practitioners have an important role to play in enabling a community to reach its goals. There is a lot to learn from our colleagues in Europe, as shown in the data on fatalities per capita where The Netherlands has always been a standout and Spain has caught up!

Their focus on the importance of developing a comprehensive network to make cycling a possibility for more people is something that has induced travel demand for cycling! 

In another recent podcast, the New York State DOT staff talked about their importance of their Strategic Highway Safety Plan and how it is directing their work. When an agency declares Vision Zero, it seems that we as practitioners are not completely embracing this with the rigor that getting to Zero would require. I understand, there is risk in how you are viewed by your peers and your local community, but if we're going to reduce deaths, we have an opportunity to lead on issues as mundane as changing design standards that reduce the speed limit of our streets with interventions, the crossing widths for people walking, or the provision of more protection for people biking similar to what you'll experience in many European communities and even cities in the U.S.  

ITE has made some great strides to introduce new ideas in the past few years and our Safety Roadmap and Action Plan is a great place to start if you're looking to be part of the change that shifts the storyline from "wasting trillions" to being a part of the solution to our safety challenge. From writing an article on safety for the ITE Journal (Item TR-8) to signing on to our ITE Safety Pledge (Item I-6 coming soon) Looking forward to seeing some of you in Orlando to continue the conversation at the Annual Meeting!

Bicycle signing/markings and traffic signals on the ITE Community

 Thanks for starting the discussion Jerry, lots to unpack here. The ITE Bicycle Signals Resource Hub has some information at the following website. I will try to tackle a few of the ideas 

Detection Types for Bicycle and Micromobility

Portland has moved away from pedestrian push buttons for bicycle detection, using inductive loops. Our past studies using all forms of video, radar, thermal, pucks, hasn't seemed to meet our requirements. New innovations may be available, so the City is studying the latest offerings for sensing techniques in our goal to reach 99% accuracy for detecting cyclists. Our next test will include new forms of detection including LIDAR and we have research underway with David Hurwitz at Oregon State University. Results to follow in 2026. 

Detector Location

I like the idea of an 80' advance detector, the Portland traffic signal design guide standard is 60 feet, but there are instances where advance detection from more than 250 feet away has lead to improved operations. In a self proclaimed "Best Bike Signal in the U.S." video, we use a connection between the signals to reduce the potential for stopping at the downstream location. I would be curious if anyone else has explored Bicycle Signal Priority using advanced logic in traffic controllers. 

Detector Marking Stencil

I got brought into this discussion since Portland has done some good work on this space. 

We have completed an experiment with a "Wait Here for Green" Stencil (using Columbia, MO as an example) and documented the current progress here. The modified stencil has been well received by the community and rates of awareness have improved significantly. 

Unfortunately, the new MUTCD elongates the detector marking significantly (the length of the new marking with text is much longer than what we believe would be needed). 

A review of some of the innovations in Portland can be found at the following blog. 

Detector Confirmation for Bicycle Traffic (Blue Light)

Portland started out with a study of whether a tattle tail light (small blue light) would serve to provide detector confirmations. This was studied by a Team at the City with some follow up research from Portland State University and Oregon State University with results here.

Portland has also had some further research focusing on the installation of Dutch Countdown timers, given that this provides more information to users. Research on this device proves that the feedback to users improves compliance when you let them know they are detected, and to indicate how long it might take to get a green light and researchers as documented in this report on findings from their observational study.

If you're interested in learning more about any of these items, especially the Dutch Countdown signal heads, we have a group of cities that are group purchasing these in the near future, so feel free to reach out to me to get involved.