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Item 4778, Engineering Department Photographic Negatives (Record Series 2613-07), Seattle Municipal Archives.
1. Actuated signals communicate that cars are more important than people.
By almost constantly giving vehicles in one direction or the other a green light but giving pedestrians a walk signal only after a button press and a delay, the actuated signal embodies an institutional belief that the passage of vehicles is more important than the passage of pedestrians. This makes pedestrians feel like intruders on the street and contributes to drivers resenting the presence of any pedestrians who might slow them down. Only streets that provide some other extremely strong attraction can survive this implicit message that people are unwelcome.
2. Actuated signals make walking much slower.
With simple timed signals, delay to pedestrians from signals is minimal. Consider a typical street system (such as the north-south streets of downtown San Francisco) with intersections every 320 feet. Walking a mile involves crossing 16 streets. With optimal timing (each light beginning its walk signal 64 seconds after the previous block's signal) there might be no delay for pedestrians from the signals, so the total time to go a mile would be the 17:36 of actual walking time at 5 feet per second. More typically (with each light on a total 60-second cycle and generous 8-second clearance interval, but not timed to match walking speed), pedestrians will experience no delay 37% of the time and an average of 19 seconds of delay the other 63% of the time, for an overall average delay of 12 seconds per intersection, 192 seconds in total, contributing to a walking time of 20:48 for the mile.
With actuated signals, on the other hand, pedestrians never have a walk signal waiting when they arrive at a corner. If their walking speed exactly matches the green lights, they actually get the worst possible delay, 64 seconds at each intersection, waiting the entire length of a cycle for their walk signal, 1024 seconds waiting, making the total mile take a horrifying 34:40 to walk. More typically, they are unsynchronized to the cycle length, so their delay is an average of half the 60-second cycle at each intersection, 480 seconds in all, making the mile take 25:36. This is a 23% time penalty over timed signals in the typical case and a 97% penalty in the worst case.
3. Actuated signals ignore human factors research for user interfaces.
Actuated traffic signals are a user interface and, if they are to provide a satisfying experience, must follow the same rules of human factors as any other user interface. The standard rule of thumb is that interface components must signal feedback within 100 msec, should complete operations within 1 sec, and must provide a progress indicator for anything that takes longer than 10 sec or the user will assume that the program has crashed and will never finish. The typical actuated signal installation provides no feedback whatsoever until the light changes 30 seconds or more later, with the entirely predictable result that people will bang on the button repeatedly trying to determine if it is broken, and then give up and cross against the light before it eventually changes. (And in many cases the sensor really is broken and the walk signal will never come.) Newer installations often do have an indicator light to provide the 100 msec feedback, but it is still extremely rare to provide a progress indicator, let alone one that gives a plausible explanation for the length of the delay.
The human factors for bicycle actuation are even worse, because these never give feedback that the signal has been actuated, and the bicycle sensors are even more likely to be missing or broken than pedestrian buttons are.
4. Actuated signals deprive pedestrians and drivers of important information.
Because the human factors of signals lead people to believe that the walk signal will never come and the delay from waiting is so great, people frequently give up and cross against the light, especially if there is a green light for vehicles in the same direction. Because the pedestrian signal still shows "don't walk" as people cross illegally, drivers are more likely to turn without looking and hit the pedestrians, and pedestrians are deprived of the knowledge of why their signal might legitimately and importantly say "don't walk," such as a left turn arrow for vehicles in the opposite direction.
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/
Other photos:
2009 01 06
From left to right:
- The High Cost of Free Parking by Donald Shoup (now signed!)
- Design of Cities by Edmund Bacon
- The New Transit Town by Dittmar & Ohland
- The Geography of Nowhere by James Kunstler
- The Death and Life of Great American Cities by Jane Jacobs
- Crabgrass Frontier by Kenneth Jackson
- The American Suburb by Jon Teaford
- Taking the High Road by Katz & Puentes
- How Women Saved the City by Daphne Spain
- Save Our Land, Save Our Towns by Hylton & Seitz
- The City Shaped by Spiro Kostof
- The Highway Code by the Department for Transport and Driving Standards Agency of Great Britain
- Signspotting by Lonely Planet
- Readings in Planning Theory edited by Campbell and Fainstein
- Urban Transportation Planning by Meyer & Miller
- Modelling Transport by Ortúzar & Willumsen
- Traffic Engineering by Roess, Prassas, & McChane
- Principles of Highway Engineering and Traffic Analysis by Mannering, Washburn, & Kilareski
- Commuting in America III by Alan Pisarski with the NCHRP, TCRP, for TRB.
- Some loose papers of research from Sweden
- A Guide to the Project Management Body of Knowledge by the Project Management Institute
- Project Management in Practice by Mantel, Meredith, Shafer, & Sutton
- Developing Management Skills by Whetten & Cameron
- Positive Leadership by Kim Cameron
- Building the Bridge As You Walk On It by Robert Quinn
- Trip Generation 8 (1 notebook & 2 books) by the Institute of Transportation Engineers
- Book of maintenance of traffic standards
- Book of work zone guidelines
- Mighty Goomba!!!
However, what's missing because it's either lower on my desk, in my backpack, or back at my apartment:
- Countless issues of ITE Journal
- Countless issues of Traffic International
- Several issues of Better Roads
- Traffic by Tom Vanderbilt
- The Boulevard Book by Allan Jacobs, Elizabeth Macdonald, Yodan Rofé
- The World Without Us by Alan Weisman
- Manual on Uniform Traffic Control Devices, 2003 Edition from the FHWA
- The Highway Capacity Manual, 2000 Edition from the Transportation Research Board
- A Policy on Geometric Design of Highways and Streets, 4th Edition from AASHTO
- And a photo of Robert Moses to counter-balance Jane Jacobs.
...I'm not keen on all the self-esteem books: none of them quite conform with the way my mind works. They're just leftover from some classes I took back in the grad school days.
While I like Jane Jacobs, I also have an infatuation with Robert Moses. I have to respect that he single-handedly became among the most powerful men ever to exist in America whilst acquiring rather little wealth. He helped form New York City today: both what we hate and what we love. His capabilities to see projects through were phenomenal, and his preference for greater good rather than individual good is a bit in line with my philosophy... though with consideration of Jane Jacobs, I do agree that Moses crossed the line on some (or many) occasions. Both were right, and both were wrong; each in different ways.
And then to pick at two others: Hylton's book is good at providing visual impacts of sprawl but is rather short on details and solutions. Kunstler's book is great at criticising but also very lacking on suggestions. Most of others provide some great commentary and suggestions, though not necessarily all of which I agree with wholeheartedly.
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/
The core of what they have changed when adding the turn arrows is switching the signal from a 60-second cycle (synchronized to match the 41st Street signal timing) to a 90-second cycle. I think this part is actually necessary if they are to have turn arrows because there just isn't time to fit all the necessary phases into 60 seconds.
So what they have done is to prioritize Broadway, giving it in the default pattern 60 seconds and 40th Street 30 seconds. The northbound and eastbound turn arrows (including their yellow arrow phases) last about 10 seconds each, leaving 50 seconds for the Broadway green and yellow phases and 20 seconds for the 40th Street green and yellow phases. The 10 seconds appears to be enough to get two cars through the turn arrow, which seems to be the appropriate number for how many get queued up in practice.
The moderately good news is that they acknowledge that 50 seconds is plenty of time to cross 40th Street, the longest leg of which is 75 feet, and give a walk signal if a pedestrian pushes the button while the light is green. This is not as good as always giving a walk signal with every green light, but is tolerable and perhaps gives some additional visibility if drivers pay attention to when the walk signal appears or doesn't appear. In practice, as the picture shows, many people don't bother to press the button, and both drivers and pedestrians miss out on the useful information the pedestrian signal is intended to provide.
The bad news is that 20 seconds is only barely long enough to cross Broadway, which is 70 feet between curbs. Their answer to this is that if a pedestrian pushes the button to cross Broadway, the next round of signals gives 45 seconds to Broadway and 45 seconds to 40th Street, giving enough time to cross. The bad news is that if the light to cross Broadway is already green, the phasing doesn't change until the next cycle, so pedestrians must wait through 20/30 seconds of green light and 45 seconds of red light before they get their walk signal. What obviously should happen here instead is for the green phase in progress to be lengthened and the walk signal lit immediately rather than making pedestrians wait for the next one.
Even better of course would be to even out the standard phase lengths a little and always give a walk signal with every green light, but really: if you know a pedestrian is present and you have the choice between giving them a walk signal now and giving them a walk signal a minute in the future, give them the walk signal now.
From a report titled "Commuter Bikeway Study," Document 2096, Published Document Collection, Seattle Municipal Archives.
Other photos:
2010 05 27
From left to right:
- A "Traffic" license plate
- The Boulevard Book by Allan Jacobs, Elizabeth Macdonald, Yodan Rofé
- Traffic by Tom Vanderbilt
- The World Without Us by Alan Weisman
- Design of Cities by Edmund Bacon
- The New Transit Town by Dittmar & Ohland
- The Geography of Nowhere by James Kunstler
- The Death and Life of Great American Cities by Jane Jacobs
- Taking the High Road by Katz & Puentes
- Crabgrass Frontier by Kenneth Jackson
- The American Suburb by Jon Teaford
- Two Billion Cars by Daniel Sperling & Deborah Gordon
- Save Our Land, Save Our Towns by Hylton & Seitz
- How Women Saved the City by Daphne Spain
- The Highway Code by the Department for Transport and Driving Standards Agency of Great Britain
- Signspotting by Lonely Planet
- Readings in Planning Theory edited by Campbell and Fainstein
- Urban Transportation Planning by Meyer & Miller
- Modelling Transport by Ortúzar & Willumsen
- Traffic Engineering by Roess, Prassas, & McChane
- Commuting in America III by Alan Pisarski with the NCHRP, TCRP, for TRB.
- Some loose papers of research from Sweden
- A Guide to the Project Management Body of Knowledge by the Project Management Institute
- Project Management in Practice by Mantel, Meredith, Shafer, & Sutton
- Developing Management Skills by Whetten & Cameron
- Building the Bridge As You Walk On It by Robert Quinn
- Book of maintenance of traffic standards
- Trip Generation 8 (1 notebook & 2 books) by the Institute of Transportation Engineers
- Book of work zone guidelines
- Mighty Goomba!!! (just barely visible)
However, what's missing because it's either lower on my desk, in my backpack, or back at my apartment:
- Countless issues of ITE Journal
- Countless issues of Traffic International
- Several issues of Better Roads
- The High Cost of Free Parking by Donald Shoup (now signed!)
- The City Shaped by Spiro Kostof
- Positive Leadership by Kim Cameron
- Principles of Highway Engineering and Traffic Analysis by Mannering, Washburn, & Kilareski
- Manual on Uniform Traffic Control Devices, 2003 Edition from the FHWA
- The Highway Capacity Manual, 2000 Edition from the Transportation Research Board
- A Policy on Geometric Design of Highways and Streets, 4th Edition from AASHTO
- And a photo of Robert Moses to counter-balance Jane Jacobs.
...I'm not keen on all the self-esteem books: none of them quite conform with the way my mind works. They're just leftover from some classes I took back in the grad school days.
While I like Jane Jacobs, I also have an infatuation with Robert Moses. I have to respect that he single-handedly became among the most powerful men ever to exist in America whilst acquiring rather little wealth. He helped form New York City today: both what we hate and what we love. His capabilities to see projects through were phenomenal, and his preference for greater good rather than individual good is a bit in line with my philosophy... though with consideration of Jane Jacobs, I do agree that Moses crossed the line on some (or many) occasions. Both were right, and both were wrong; each in different ways.
And then to pick at two others: Hylton's book is good at providing visual impacts of sprawl but is rather short on details and solutions. Kunstler's book is great at criticising but also very lacking on suggestions. Most of others provide some great commentary and suggestions, though not necessarily all of which I agree with wholeheartedly.
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/
Item 69185, Engineering Department Photographic Negatives (Record Series 2613-07), Seattle Municipal Archives.
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/
The traffic speed on any street with progressively timed signals (that is not favoring one direction over the other) will be the length of the block (in feet) divided by the length of the signal phase times ~0.68182 (3600 / 5280). For example, the speed on Valencia Street is 13.3 mph because the blocks are 586.25 feet long and the lights change every 30 seconds.
"Happier, Healthier, Sexier, and Smarter: Transportation and the Secret of Life"
Tuesday, January 10, 2012
National Capital Planning Commission
An event arranged by the Coalition for Smarter Growth
Sustainable transportation is composed of strategic and thoughtful investments that help a community achieve its larger economic vitality, social equity, ecological diversity, quality of life, and other goals. Transportation is inseparable from land use planning, economic development, and even human health and happiness.
Although many sectors are embracing the challenges of long term sustainability, transportation planning lags behind with many policies and standards still rooted in a bygone era. Please join in a discussion about the compelling need and tremendous opportunities to plan, implement, and communicate sustainable transportation strategies for the nation and future.
About the Speaker
Jeff Tumlin is a nationally known transportation planner, owner and principal for Nelson/Nygaard Associates in San Francisco, CA, and author of the forthcoming book, "Sustainable Transportation Planning: Tools for Creating Vibrant, Healthy, and Resilient Communities."
The "Then" photo in 1944 (see comments) shows us a shining example of modernity. Just a few years earlier, the Madison Street Cable Car was ripped out and replaced with bus service. The odd intersection of Madison with 14th and Pike still posed a challenge, though. Over the years we've tried many attempts with repositioned triangles, stop signs replaced with stop lights, even restricting the natural flow of pedestrians.
It's still goofy, though, and probably a good candidate for closure of one driving motion. We'll keep fiddling with it, because we're a city of engineers. Check out this shot of the cable car during regrading downtown!
"Happier, Healthier, Sexier, and Smarter: Transportation and the Secret of Life"
Tuesday, January 10, 2012
National Capital Planning Commission
An event arranged by the Coalition for Smarter Growth
Sustainable transportation is composed of strategic and thoughtful investments that help a community achieve its larger economic vitality, social equity, ecological diversity, quality of life, and other goals. Transportation is inseparable from land use planning, economic development, and even human health and happiness.
Although many sectors are embracing the challenges of long term sustainability, transportation planning lags behind with many policies and standards still rooted in a bygone era. Please join in a discussion about the compelling need and tremendous opportunities to plan, implement, and communicate sustainable transportation strategies for the nation and future.
About the Speaker
Jeff Tumlin is a nationally known transportation planner, owner and principal for Nelson/Nygaard Associates in San Francisco, CA, and author of the forthcoming book, "Sustainable Transportation Planning: Tools for Creating Vibrant, Healthy, and Resilient Communities."
"Happier, Healthier, Sexier, and Smarter: Transportation and the Secret of Life"
Tuesday, January 10, 2012
National Capital Planning Commission
An event arranged by the Coalition for Smarter Growth
Sustainable transportation is composed of strategic and thoughtful investments that help a community achieve its larger economic vitality, social equity, ecological diversity, quality of life, and other goals. Transportation is inseparable from land use planning, economic development, and even human health and happiness.
Although many sectors are embracing the challenges of long term sustainability, transportation planning lags behind with many policies and standards still rooted in a bygone era. Please join in a discussion about the compelling need and tremendous opportunities to plan, implement, and communicate sustainable transportation strategies for the nation and future.
About the Speaker
Jeff Tumlin is a nationally known transportation planner, owner and principal for Nelson/Nygaard Associates in San Francisco, CA, and author of the forthcoming book, "Sustainable Transportation Planning: Tools for Creating Vibrant, Healthy, and Resilient Communities."
Fences are the newest traffic engineering solution for achieving good traffic flow; they control people, by blocking the path of least resistence. To catch a bus accross the street becomes incovenient; a long walk for a senior, for a mother with kids and anyone loaded with goods.
Starbucks is missing in both pictures, not in the urban nor in the suburban.
To serve both bus directions well, a coffe shop would, ideally, be located on the fence! out the door and on to a bus! That can happen in a Fused Grid road configuration (see Wiki)
In the current mode, it will be a long wait for the bus and the starbucks and a long stretch for convenience and comfort-minded transportation planning.
if we level fitzrovia and start again with a rational free-flowing road layout [the motorway to the right is tottenham court road, across the top is euston road]...
"Happier, Healthier, Sexier, and Smarter: Transportation and the Secret of Life"
Tuesday, January 10, 2012
National Capital Planning Commission
An event arranged by the Coalition for Smarter Growth
Sustainable transportation is composed of strategic and thoughtful investments that help a community achieve its larger economic vitality, social equity, ecological diversity, quality of life, and other goals. Transportation is inseparable from land use planning, economic development, and even human health and happiness.
Although many sectors are embracing the challenges of long term sustainability, transportation planning lags behind with many policies and standards still rooted in a bygone era. Please join in a discussion about the compelling need and tremendous opportunities to plan, implement, and communicate sustainable transportation strategies for the nation and future.
About the Speaker
Jeff Tumlin is a nationally known transportation planner, owner and principal for Nelson/Nygaard Associates in San Francisco, CA, and author of the forthcoming book, "Sustainable Transportation Planning: Tools for Creating Vibrant, Healthy, and Resilient Communities."
"Happier, Healthier, Sexier, and Smarter: Transportation and the Secret of Life"
Tuesday, January 10, 2012
National Capital Planning Commission
An event arranged by the Coalition for Smarter Growth
Sustainable transportation is composed of strategic and thoughtful investments that help a community achieve its larger economic vitality, social equity, ecological diversity, quality of life, and other goals. Transportation is inseparable from land use planning, economic development, and even human health and happiness.
Although many sectors are embracing the challenges of long term sustainability, transportation planning lags behind with many policies and standards still rooted in a bygone era. Please join in a discussion about the compelling need and tremendous opportunities to plan, implement, and communicate sustainable transportation strategies for the nation and future.
About the Speaker
Jeff Tumlin is a nationally known transportation planner, owner and principal for Nelson/Nygaard Associates in San Francisco, CA, and author of the forthcoming book, "Sustainable Transportation Planning: Tools for Creating Vibrant, Healthy, and Resilient Communities."
these are the uses built above the new deck level. oxford street at the bottom continues as a major shopping 'street' at deck level, but note that there is no corresponding road at ground level.
"Happier, Healthier, Sexier, and Smarter: Transportation and the Secret of Life"
Tuesday, January 10, 2012
National Capital Planning Commission
An event arranged by the Coalition for Smarter Growth
Sustainable transportation is composed of strategic and thoughtful investments that help a community achieve its larger economic vitality, social equity, ecological diversity, quality of life, and other goals. Transportation is inseparable from land use planning, economic development, and even human health and happiness.
Although many sectors are embracing the challenges of long term sustainability, transportation planning lags behind with many policies and standards still rooted in a bygone era. Please join in a discussion about the compelling need and tremendous opportunities to plan, implement, and communicate sustainable transportation strategies for the nation and future.
About the Speaker
Jeff Tumlin is a nationally known transportation planner, owner and principal for Nelson/Nygaard Associates in San Francisco, CA, and author of the forthcoming book, "Sustainable Transportation Planning: Tools for Creating Vibrant, Healthy, and Resilient Communities."
"Happier, Healthier, Sexier, and Smarter: Transportation and the Secret of Life"
Tuesday, January 10, 2012
National Capital Planning Commission
An event arranged by the Coalition for Smarter Growth
Sustainable transportation is composed of strategic and thoughtful investments that help a community achieve its larger economic vitality, social equity, ecological diversity, quality of life, and other goals. Transportation is inseparable from land use planning, economic development, and even human health and happiness.
Although many sectors are embracing the challenges of long term sustainability, transportation planning lags behind with many policies and standards still rooted in a bygone era. Please join in a discussion about the compelling need and tremendous opportunities to plan, implement, and communicate sustainable transportation strategies for the nation and future.
About the Speaker
Jeff Tumlin is a nationally known transportation planner, owner and principal for Nelson/Nygaard Associates in San Francisco, CA, and author of the forthcoming book, "Sustainable Transportation Planning: Tools for Creating Vibrant, Healthy, and Resilient Communities."
it's easy to forget how bombed and decrepit many now-desirable areas of central london were in the early 60s. this is what enabled the startling schemes that follow.
and above the rational road net we build a pedestrian-only deck as a new 'ground level', which doesn't need to follow the road layout...
Walking Salon examining design history of 16th Street NW; League of Sidewalk Superintendents - www.meetup.com/The-League-of-Sidewalk-Superintendents/