In addition, in areas with very high traffic, like London, area-coordinated adaptive traffic light systems (see SCOOT/SCATS) are used to keep traffic flowing smoothly, stop congestion from blocking junctions, prioritise emergency services and more. These systems are very good at what they do.
Traffic lights are also used to give priority to pedestrians and cyclists on junctions where it would be unsafe to rely on zebra crossings or pedestrian priority - think sharp and low visibility corners.
As far as roundabouts go, the UK has been replacing big multi-lane roundabouts in areas with lots of pedestrians and cyclists with two-way-traffic horse shoes (e.g. Old Street and E&C, plus others outside of London). This allows the centre of the roundabout to be used as public space, and has been found to be safer for vulnerable road users.
I'm all for light-free junctions where possible, and light-free roundabouts work REALLY well in low/medium traffic. But you can't just abolish traffic lights - unless we also abolish cars at the same time.
Do you have a link to one of these "two-way horse shoes" on Google maps or similar?
I'm curious how they solve the problem of needing to taking the 3rd exit on a multi-lane roundabout while on a bicycle.
Look up the Old Street roundabout and Elephant and Castle Roundabout.
The essence of of is segregated cycle lanes with cycle-only traffic lights. Nothing magic.
Neither of them are fully separated (yet at least - they're still being worked on), but they're a lot better than what came before.
Trafalgar Square also used to be a roundabout back in the day, though it got converted to a peninsula before bicycles were fashionable so that's not a great example.
Highbury Corner is another example you can look at.
Pretty simple. The section of road between 3rd exit and the 4th (which is also where you enter) is completely removed.
So taking the 3rd exit on a bike either means following the road all the way around, or just going directly from the entrance to the 3rd exit, as cycle lane is usually preserved where the road used to be.
I looked at that E&C "horseshoe" - it still looks hairy if you're riding north on the A3 and want to turn right into the A201, given the number of crossings of busy roads with no traffic signals. But better than some of the busy 3-lane roundabouts I've had to navigate here with no provision for bicycles (or pedestrians really) at all.
Every junction on the E&C horseshoe if traffic light controlled, including all the cycle crossings.
The safest route for bikes is to take the segregated bike route at the bottom of the horseshoe, then using the mixed bike and pedestrian crossing to go directly over the mixed used paved area, then use the mixed crossing on the other side to join the A201. Either that, or use the segregated cycle path, then horseshoe near London Rd.
But honestly, on a bike you would just avoid the horseshoe completely. There’s usually better cycle routes that are more direct, and avoid large junctions like the E&C horseshoe.
Traffic lights are also used to give priority to pedestrians and cyclists on junctions where it would be unsafe to rely on zebra crossings or pedestrian priority - think sharp and low visibility corners.
As far as roundabouts go, the UK has been replacing big multi-lane roundabouts in areas with lots of pedestrians and cyclists with two-way-traffic horse shoes (e.g. Old Street and E&C, plus others outside of London). This allows the centre of the roundabout to be used as public space, and has been found to be safer for vulnerable road users.
I'm all for light-free junctions where possible, and light-free roundabouts work REALLY well in low/medium traffic. But you can't just abolish traffic lights - unless we also abolish cars at the same time.