In Gloucester here in the UK where I live, we have 4 major roundabouts on what we call the A38 Ringroad. As I don't know what you guys call them or
whether or not you have them, I'll explain. They are strategicly placed to control the flow of traffic from minor roads, to the ring road and also
feed (by use of lanes, to trading estates and businesses)
This has tended to work well in the past, until a couple of years ago, when the local authorities decided to place pedestrian crossings, each
controlled by traffic lights, just short of the roundabouts.
So imagine the scene.............................
You are bombing along at 50 mph, then hit a 30 mph area then suddenly a pedestrian who is far too lazy to drive to work, hits the button and
me! The lights immediately go
red and the cars in front going round the roundabout almost collide because even though the limit is 30mph, it
is pretty hard to stop when some idiot walks across the road in front of you.
Another annoying thing that happens first thing in the morning, is along Eastern Avenue, a three lane part of the A38, it gets chockabloc during rush
hour. The central reservation, is a grassed area with a couple of trees and a Gatso '30' speed camera.
Now, with vehicles nose to tail on what we call 'Walls' Roundabout, with pedestrians holding up the traffic and two lane traffic [into Gloucester]
often backing up across the roundabout, Emergency Vehicles find it often takes them four to five or even six minutes to drive along 100 metres and
cross over Walls Roundabout.
The problem is, drivers have nowhere to go. There are no 'emergency vehicle only' lanes and drivers are reluctant to drive over the curbing stones
in the near and offside lanes with the result of possible damage to their vehicles.
I do like your idea of multi coloured traffic lights or better yet, perhaps car makers could put some sort of device in the dashboard that is linked
to the lights and the device could perhaps change the lights if there were no other traffic.