Roundabout would not be considered here because of the high volumes on the priority road. Especially in proportion to the sidestreet. America considers roundabouts where overall volumes are less than 1000 vehicles per hour (1500 for dual lanes). Above that, roundabouts lose efficiency. Additionally, roundabouts cost more due to more materials and land necessary. If another more efficient option uses less concrete and land, then that option is considered.
And yes, America builds roundabouts. America started building them in the 90s after France's campaign. America just has stricter criteria where they work best.
@@traffic.engineer Shouldn’t safety come first over speed? That should be prioritized. The fact this country has so many annual deaths from car accidents is insane. So many other European countries have significantly less annual deaths with their safer road design, which the design not only benefits drivers, but also people outside of cars. People outside of cars are just not prioritized in American and that’s awful.
@@localnyraccoon Efficiency is not about high speed. It is about reducing unnecesssary, unwarranted, and unrealistic delays. Efficiency is relative to the environment and the purpose it serves. A 35-45 MPH suburban collector road is still efficient, but drivers are not going to request a road to be 70 MPH to make more efficient. When roads are not efficient despite the safety benefit, it leads to disrespect for control, in which drivers take more risk to make up the lost time. That is why signals, all-way stops, speed humps, and crosswalks have specific warrants where they are installed. Otherwise, driver will not see the benefit despite an attempt to be safer. Roundabouts have a specific criteria where they work best, such as low volume rural intersections and suburban roads. They are inefficient in urban and heavy arterials. America had traffic circles in metro cities for over half a century, even before Europe. They did not only move traffic slowly, but they also had a bad safety record. It was not until the modern roundabout was developed that changed the operations, which made them safer and quicker. But again, they do not work well in heavy volumes. Just like a cloverleaf interchange, they work well in low volume because vehicles conflict less while need less stoppage. When volumes rise, it increases the conflicts which leads to more stopping, more queues, and more risk of crash (both at the merging sections and the end of stopped traffic). At that point, a form of stop control will be necessary. The roundabout would not work on this road because the high volumes of traffic would need to stop for one vehicle crossing from the low volume sidestreet (almost like a signal). This would violate driver expectations as well as create queues on the main road. Instead the low volume sidestreet interacts with one direction, merges with traffic, then interacts with the other direction separately to go left. It is similar to roundabouts, where a vehicle only has to look in one direction to go or not, as well as reducing the number of conflict points in one tiny space.
@@localnyraccoon RCUTs offer significant safety improvements on their own and, by prioritizing main route traffic, are more consistent with what drivers expect on a high-speed corridor. Having drivers slow from 65 to 25 for a roundabout creates safety issues with increased rear-end collisions.
This should be done in Wisconsin, too. My father lives near one of these highway crossings.
How about a roundabout? Very effective outside of America.
Roundabout would not be considered here because of the high volumes on the priority road. Especially in proportion to the sidestreet.
America considers roundabouts where overall volumes are less than 1000 vehicles per hour (1500 for dual lanes). Above that, roundabouts lose efficiency.
Additionally, roundabouts cost more due to more materials and land necessary. If another more efficient option uses less concrete and land, then that option is considered.
And yes, America builds roundabouts. America started building them in the 90s after France's campaign. America just has stricter criteria where they work best.
@@traffic.engineer Shouldn’t safety come first over speed? That should be prioritized. The fact this country has so many annual deaths from car accidents is insane. So many other European countries have significantly less annual deaths with their safer road design, which the design not only benefits drivers, but also people outside of cars. People outside of cars are just not prioritized in American and that’s awful.
@@localnyraccoon Efficiency is not about high speed. It is about reducing unnecesssary, unwarranted, and unrealistic delays. Efficiency is relative to the environment and the purpose it serves. A 35-45 MPH suburban collector road is still efficient, but drivers are not going to request a road to be 70 MPH to make more efficient. When roads are not efficient despite the safety benefit, it leads to disrespect for control, in which drivers take more risk to make up the lost time.
That is why signals, all-way stops, speed humps, and crosswalks have specific warrants where they are installed. Otherwise, driver will not see the benefit despite an attempt to be safer.
Roundabouts have a specific criteria where they work best, such as low volume rural intersections and suburban roads. They are inefficient in urban and heavy arterials. America had traffic circles in metro cities for over half a century, even before Europe. They did not only move traffic slowly, but they also had a bad safety record. It was not until the modern roundabout was developed that changed the operations, which made them safer and quicker. But again, they do not work well in heavy volumes. Just like a cloverleaf interchange, they work well in low volume because vehicles conflict less while need less stoppage. When volumes rise, it increases the conflicts which leads to more stopping, more queues, and more risk of crash (both at the merging sections and the end of stopped traffic). At that point, a form of stop control will be necessary.
The roundabout would not work on this road because the high volumes of traffic would need to stop for one vehicle crossing from the low volume sidestreet (almost like a signal). This would violate driver expectations as well as create queues on the main road. Instead the low volume sidestreet interacts with one direction, merges with traffic, then interacts with the other direction separately to go left. It is similar to roundabouts, where a vehicle only has to look in one direction to go or not, as well as reducing the number of conflict points in one tiny space.
@@localnyraccoon RCUTs offer significant safety improvements on their own and, by prioritizing main route traffic, are more consistent with what drivers expect on a high-speed corridor. Having drivers slow from 65 to 25 for a roundabout creates safety issues with increased rear-end collisions.
lets face it, the real question is.. should be build them in cities skyline?
This is very interesting, thank you! Do you know if these RCUTs are being considered in other states as well?
Many states already have them.
how much would it cost to implement these new intersections?