The main street for all the businesses in a nearby city is set up so you can hit all green lights going down the road from 2pm-~6pm, however if you get caught at a SINGLE light, you’re going to hit reds all the way down.
So it’s become “oh that light is about to change better engage T U R B O M O D E and speed 20mph over the limit to beat this light and stay with the greens” which turns out very predictably at least once a month.
Last week a car rolled twice while speeding up to beat the light and clipped an ambulance coming from another street.
The DOT planning department I worked for (in the 80s) had studies showing that synchronizing the lights 10-15mph ABOVE the speed limit kept traffic flowing “optimally” to minimize congestion without having to expand the infrastructure (mostly: lanes). Even today I see city traffic lights synchronized mostly +10mph over the posted limit in the direction of highest flow on major arteries - you can tell when you “make” one yellow light, then lock in cruise control at limit+10 and “make” the next 3+ lights at exactly the same flash of yellow as you approach.
They do this to delay improvement projects like additional lanes, straightening curves, etc. by showing a higher “level of service” for the roadway than they would have with the lights synchronized at, say: speed limit -10mph. If you’re talking about a 45mph roadway, moving the cars at 55mph instead of 35mph means 157% as many vehicles per hour at the same spacing, and we all know that people don’t actually increase following distances at higher speeds, so… it’s a real, and significant difference. Not as significant as getting people to carpool, or take public transit, but that’s about as likely to happen as increasing following distances.
The main street for all the businesses in a nearby city is set up so you can hit all green lights going down the road from 2pm-~6pm, however if you get caught at a SINGLE light, you’re going to hit reds all the way down.
So it’s become “oh that light is about to change better engage T U R B O M O D E and speed 20mph over the limit to beat this light and stay with the greens” which turns out very predictably at least once a month.
Last week a car rolled twice while speeding up to beat the light and clipped an ambulance coming from another street.
The DOT planning department I worked for (in the 80s) had studies showing that synchronizing the lights 10-15mph ABOVE the speed limit kept traffic flowing “optimally” to minimize congestion without having to expand the infrastructure (mostly: lanes). Even today I see city traffic lights synchronized mostly +10mph over the posted limit in the direction of highest flow on major arteries - you can tell when you “make” one yellow light, then lock in cruise control at limit+10 and “make” the next 3+ lights at exactly the same flash of yellow as you approach.
They do this to delay improvement projects like additional lanes, straightening curves, etc. by showing a higher “level of service” for the roadway than they would have with the lights synchronized at, say: speed limit -10mph. If you’re talking about a 45mph roadway, moving the cars at 55mph instead of 35mph means 157% as many vehicles per hour at the same spacing, and we all know that people don’t actually increase following distances at higher speeds, so… it’s a real, and significant difference. Not as significant as getting people to carpool, or take public transit, but that’s about as likely to happen as increasing following distances.