7 ms·

In the USA, the Manual of Uniform Traffic Control Devices has an (I think) reasonable requirements for crossing durations but almost no further recommendations

In the USA, the Manual of Uniform Traffic Control Devices has an (I think) reasonable requirements for crossing durations but almost no further recommendations about maximum wait times. This results in completely idiotic timing programs of the signals everywhere that encourage people to cross when cars have a green light. If you want to change it to be more pedestrian friendly, it can cost $20k+ because the signals are programmed in a 40 year old language that only a very small group of highly paid traffic engineers know how to write.

lostlogin 3y ago
> If you want to change it to be more pedestrian friendly, it can cost $20k+ Per set of lights?!
- blindstitch 3y ago
  I could be wrong. I can't locate the source I found originally. Online chatter for a city planning forum said around 20k. This very old information says it's a lot less, but I don't think these numbers would be accurate for a small town with only enough money to fix their signals piecemeal by contractors, or for one that involves smarter programming that works around MUTCD. https://www.itskrs.its.dot.gov/its/benecost.nsf/ID/215f723db93d293c8525725f00786fd8 https://www.itskrs.its.dot.gov/its/benecost.nsf/ID/215f723db...
unflxw 3y ago
> the signals are programmed in a 40 year old language that only a very small group of highly paid traffic engineers know how to write. This is interesting. What language is this, or more generally, where can I read more about this?
- mschild 3y ago
  edit: Whops. Just realized theyre talking about the US. Disregard my comment. I'm not entirely sure what OP is talking about, but I think they use a system called SCATS.[0] Looks like the system is actually pretty widely used in some other countries as well. [0] https://www.scats.nsw.gov.au/solutions/products https://www.scats.nsw.gov.au/solutions/products
- yamazakiwi 3y ago
  Traffic light systems are designed using software such as LINSIG, TRANSYT, CORSIM/TRANSYT-7F or VISSIM. Per wikipedia different countries use different systems over time: e.g. Sydney: 3,400 traffic signals co-ordinated by the Sydney Co-ordinated Adaptive Traffic System (SCATS). Designed and developed by RTA, the system was first introduced in 1963 and progressively developed since then. By October 2010, SCATS was licensed to 33,200 intersections in 144 cities across 24 countries worldwide, including Singapore, Hong Kong, Dublin, Tehran and Minneapolis and Detroit.[19][23][24] https://en.wikipedia.org/wiki/Traffic_light_control_and_coordination https://en.wikipedia.org/wiki/Traffic_light_control_and_coor...
- nwahs_op 3y ago
  If you are super bored. Here is a manual that is VERY detailed explanation on programming traffic signals. I give this to new engineers and technicians to look at when they first start. Chapters 5 and 6 get into the actual programming of the signal. https://ops.fhwa.dot.gov/publications/fhwahop08024/index.htm https://ops.fhwa.dot.gov/publications/fhwahop08024/index.htm
nwahs_op 3y ago
I happen to be a traffic engineer who operates signals in the USA. We may not have the most advanced technology but I can assure that we don't not write code to operate our signals. We do enter different parameters that govern the amount of time that you have to wait. In most situations it comes down to if you want to favor vehicles or if you want to favor pedestrians. As everyone has mentioned it is difficult to accommodate both as they would like. Also as government worker I can assure we are not highly paid. We make a decent living but there is actually a shortage of people right now that want to do the work.
- nwahs_op 3y ago
  Sorry one last thing. I do try to ride my electric scooter to work. :)
- blindstitch 3y ago
  I trust my sources (mainly, a city planner that's been working here for 30 years). Certain engineering specialists out here sometimes make absolutely absurd amounts of money because they work on contracts with such limited scope, the equivalent of 600k or more a year. Also, I think the notion of having to balance pedestrians' interests with drivers' is a cultural thing that filters down from the MUTCD and into traffic engineering. Drivers create almost all the risk associated with our road system yet their interests are prioritized highly. Traffic engineers are bound to this deadly model that prioritizes drivers, because road construction projects are not given government funds (which they often completely rely on) unless they conform to MUTCD.

lostlogin 3y ago

> If you want to change it to be more pedestrian friendly, it can cost $20k+ Per set of lights?!

blindstitch 3y ago
I could be wrong. I can't locate the source I found originally. Online chatter for a city planning forum said around 20k. This very old information says it's a lot less, but I don't think these numbers would be accurate for a small town with only enough money to fix their signals piecemeal by contractors, or for one that involves smarter programming that works around MUTCD. https://www.itskrs.its.dot.gov/its/benecost.nsf/ID/215f723db93d293c8525725f00786fd8 https://www.itskrs.its.dot.gov/its/benecost.nsf/ID/215f723db...

unflxw 3y ago

> the signals are programmed in a 40 year old language that only a very small group of highly paid traffic engineers know how to write. This is interesting. What language is this, or more generally, where can I read more about this?

mschild 3y ago
edit: Whops. Just realized theyre talking about the US. Disregard my comment. I'm not entirely sure what OP is talking about, but I think they use a system called SCATS.[0] Looks like the system is actually pretty widely used in some other countries as well. [0] https://www.scats.nsw.gov.au/solutions/products https://www.scats.nsw.gov.au/solutions/products
yamazakiwi 3y ago
Traffic light systems are designed using software such as LINSIG, TRANSYT, CORSIM/TRANSYT-7F or VISSIM. Per wikipedia different countries use different systems over time: e.g. Sydney: 3,400 traffic signals co-ordinated by the Sydney Co-ordinated Adaptive Traffic System (SCATS). Designed and developed by RTA, the system was first introduced in 1963 and progressively developed since then. By October 2010, SCATS was licensed to 33,200 intersections in 144 cities across 24 countries worldwide, including Singapore, Hong Kong, Dublin, Tehran and Minneapolis and Detroit.[19][23][24] https://en.wikipedia.org/wiki/Traffic_light_control_and_coordination https://en.wikipedia.org/wiki/Traffic_light_control_and_coor...
nwahs_op 3y ago
If you are super bored. Here is a manual that is VERY detailed explanation on programming traffic signals. I give this to new engineers and technicians to look at when they first start. Chapters 5 and 6 get into the actual programming of the signal. https://ops.fhwa.dot.gov/publications/fhwahop08024/index.htm https://ops.fhwa.dot.gov/publications/fhwahop08024/index.htm

nwahs_op 3y ago

I happen to be a traffic engineer who operates signals in the USA. We may not have the most advanced technology but I can assure that we don't not write code to operate our signals. We do enter different parameters that govern the amount of time that you have to wait. In most situations it comes down to if you want to favor vehicles or if you want to favor pedestrians. As everyone has mentioned it is difficult to accommodate both as they would like. Also as government worker I can assure we are not highly paid. We make a decent living but there is actually a shortage of people right now that want to do the work.

nwahs_op 3y ago
Sorry one last thing. I do try to ride my electric scooter to work. :)
blindstitch 3y ago
I trust my sources (mainly, a city planner that's been working here for 30 years). Certain engineering specialists out here sometimes make absolutely absurd amounts of money because they work on contracts with such limited scope, the equivalent of 600k or more a year. Also, I think the notion of having to balance pedestrians' interests with drivers' is a cultural thing that filters down from the MUTCD and into traffic engineering. Drivers create almost all the risk associated with our road system yet their interests are prioritized highly. Traffic engineers are bound to this deadly model that prioritizes drivers, because road construction projects are not given government funds (which they often completely rely on) unless they conform to MUTCD.