Showing posts with label traffic signals. Show all posts
Showing posts with label traffic signals. Show all posts

Saturday, 17 November 2012

Discussing countdown timers on Linkedin

Linkedin is a professional network on the Internet with more than 187 million members in over 200 countries and territories. It is like the Facebook of professionals. One interesting aspect of Linkedin is the groups which are a forum that some very interesting discussions take place. It is also a valuable source of information. I posted my previous blog entry on countdown timers at pedestrian traffic signals on Traffic Engineer and Transportation Planner Network group with a question whether this is an idea worth investing on or should we look for a totally different approach when it comes to pedestrian traffic in busy CBD intersections. I was very pleased to see that this topic sparkled a very interesting conversation. Traffic and transport professionals from around the world posted their comments on the issue. Some of them shared links to study reports on countdown timers’ trials on different countries. The majority of the responses were in favour of installing such devices on traffic lights. Here are some of the comments:

Ray Guarino, Transportation Planner at Old Colony Planning Council, Brockton, Massachusetts: “Yes, they are worth the investment. In busy urban areas these countdown timers work great. If you want to see them in action at busy intersections, and you are the USA, go to the corner of Boylston and Tremont in Boston, Massachusetts.
                                                                                                                
Jim Lizzi, Senior Transportation Engineer at City of Irvine, Orange County, California: “I support the use of countdown timers simply because the information transmitted to pedestrians is of value.” and “With countdown timers, at least pedestrians know for sure when they should definitely NOT start crossing. The bottom line for me is that safety--of all kinds--is enhanced through understanding.”

Jakob Helmboldt, Pedestrian, Bicycle & Trails Coordinator at City of Richmond, Virginia: “In the US countdowns will soon be mandatory (end of 2013 is the current compliance date). Countdowns do have benefits, and FHWA wouldn't be requiring their use if the experimental use showed significant impaired safety. More information is always better than less when it can be conveyed with ease which is the case with a countdown signal. That said, there are always negative externalities possible, but on balance they are an improvement.”

Jeff McMullen, Chief Engineering Technician ITS/TOC at City of Fresno, California: “I agree that the countdown timers are great for pedestrians however, although I have no data to back this up other than observation, motorists are using the countdown timers also. When they see that the time is about to expire they (the aggressive drivers) tend to speed up to ensure they can make it through the signal.”  

Chuck Weaver, Senior Designer at Brudis & Associates, Baltimore, Maryland: “I've been designing intersection in MD for years....we are upgrading to APS/CPS almost everywhere”

Tony Earl, Head of Network Performance at Transport for London, Redhill, United Kingdom: “I am currently rolling out Pedestrian Countdown at Traffic Signals (PCaTS) to 200 signals with all red to traffic Pedestrian Stages in London following a study undertaken on behalf of Transport for London by TRL. This is now approved for use in the whole of England. You may find the study report of interest.

Martin Huang, Traffic Engineer at Tauranga City Council, New Zealand: “We have also installed some countdown timers at one of our signalised intersections in our city. From my observations and previous research undertaken in New Zealand, it appears that the benefits from the device are more qualitative than quantitative. About 90% of the interviewees are positive about the installation while only several percentages of crash and compliance rate have changed. To me personally, I see it as enabling to provide clear messages for pedestrians to make an informed decision. Teenagers can dash across the road with less than 10 seconds but the elderly would be safely to wait for next cycle even if it is 15+ seconds left.” and “Just for your information, there are 2 research reports about trials of countdown timers application in Auckland and Wellington and their links are shown below.
http://www.nzta.govt.nz/resources/research/reports/428/
http://www.ipenz.org.nz/ipenztg/papers/2007/C4a_HooperVencatTse.pdf

Pravin Dayaram, Director at Traffic and Transportation Engineers Ltd, New Zealand: “n Auckland, the countdown timers seem to have been implemented only at (or in conjunction with the change to) what we term locally as 'Barnes Dances' (all traffic stopped pedestrian movements cross at the same time and named after the developer). My observations indicate that there is significantly less non-compliance (crossing during the short flashing-red man phase)…”
 District Department of Transportation Columbia

Glenn Cole, Manager, Technical Information Programs at Transportation Association of Canada, Ottawa, Canada: “The Transportation Association of Canada (Traffic Operation and Management Standing Committee) put together a small study: Informational Report on Pedestrian Countdown Signals. It's available on line at
http://wiki.tac-atc.ca/twiki/pub/ChiefEngineers/PedestrianCountdown/Project_253_-_Optional_Use_of_Pedestrian_Countdown_Timers.PDF

The story Rob Klug, Traffic Signal Engineer at Clark County Public Works Portland, Oregon shared with the group was very interesting: “My favorite citizen interaction was with an elderly person who approached me at an intersection we just installed the countdown timers at, where I was working on the cabinet. She told me that she really appreciated all the extra time that she was given by these new countdown heads. She never got across the street within the flashing don't walk, but all the extra time we gave her with the new heads made it so that she could get across the street with 4 or 5 seconds to spare. I explained that we did not change any settings on the control equipment, but she was probably adjusting her walk speed based on the time she saw was left on the countdown.  She crossed her arms, and said in a very stern voice "I know you changed the timing. I never was able to cross within the time, now I can". I told her the only thing that made sense. "You are welcome", and went back to work.”

Image from 7 News video
We are living in a new era of professional and scientific communication and dialogue. The duty of mobility practitioners is to make an effort to be part of this new world, use the available means in a responsible way and share knowledge and experience.

Friday, 19 October 2012

Pedestrian signals countdown timers. Time to move on.

 Adelaide Street and Edward Street
  • Adelaide Street and Albert Street pedestrian crossing
  • Eagle Street and Wharf Street and Queen Street
  • George Street at Queen Street pedestrian crossing
  • Charlotte Street and Edward Street
All these intersections are located in Brisbane's CBD and have a high number of pedestrians using them. 


The countdown works during the Flashing Don’t Walk interval. This is a time between the Green Man and the Red Man when the Red Man is flashing.  That interval is not used in Greece and most European countries. Under Australian and Queensland road rules (231) the pedestrian is not allowed to start crossing during the Flashing Don’t Walk interval. 


The operation of the countdown timers during the flashing red interval raised a lot of questions and especially whether this actually results to pedestrians crossing illegally. This same choice was made in a similar trial case in Sydney in 2010 where the specific choice was made simply because this type of countdown was most compatible with adaptive traffic control, used in Sydney (SCATS traffic control). I don't know exactly why the same choice was made in Brisbane but I guess that the fact that SCATS is also used here, played some role in this choice.

  • Safety: There was no net change in pedestrian safety–while late starters were more successful finishing crossing (prior to the start of the SDW interval) where PCTs were installed, the late starters were offset by a reduction in pedestrians starting during the Walk interval.
  • Compliance: The level of compliance by pedestrians appears to have decreased at wider crossings where PCTs were installed. There was an increase in late starters that started crossing during the FDW interval, although non-compliant vehicles may have contributed tothis effect.
  • Amenity: Results suggested that pedestrian amenity may have been improved due to the reduction in the number of pedestrians required to wait until the next Walk interval to cross.
Probably the results of the trial period in Brisbane would not be much different and this may result in Brisbane CC not going through with the full programmed installation.

But the evolution for pedestrian traffic in cities and especially in the CBD areas has just started. And traffic signal countdown timers is only a small part of it. The plethora of different solutions for counters across the world is amazing. There are even some that are animated as this one in Auckland.


But the real issue is to prioritize pedestrian traffic over to vehicle traffic in the CBD areas. After all, the research has shown that after a period of 30 to 45 seconds of waiting, pedestrians become more risky, impatient and were more likely to cross whenever they could regardless of the pedestrian signal displays.
So we have to start thinking for pedestrian traffic similarly to how we think for cars when we programming traffic signal operations. How about green waves for pedestrians across roads linking major railway or metro stations to the core of CBD for example? Or even restricting vehicle turning movements at intersections during pedestrian traffic peak hours. We have to be more brave and pilot projects and trial periods are tools that allow us to.


Tuesday, 20 March 2012

Crosstown traffic

You jump in front of my car when you,
you know all the time
Ninty miles an hour, girl, is the speed I drive
You tell me it's alright, you don't mind a little pain
You say you just want me to take you for a drive

You're just like crosstown traffic
So hard to get through to you
Crosstown traffic
I don't need to run over you
Crosstown traffic
All you do is slow me down
And I'm tryin' to get on the other side of town

I'm not the only soul who's accused of hit and run
Tire tracks all across your back
I can, I can see you had your fun
But, darlin' can't you see my signals turn from green to red
And with you I can see a traffic jam straight up ahead

You're just like crosstown traffic
So hard to get through to you
Crosstown traffic
I don't need to run over you
Crosstown traffic
All you do is slow me down
And I got better things on the other side of town

Jimmy Hendrix, November 21, 1968