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Roundabouts are fine for cars on slow to medium speed roads - 20 to 40mph at a push. But they are a lot less efficient for longer trips. You don't get roundabou
by barrkel 8y ago
Roundabouts are fine for cars on slow to medium speed roads - 20 to 40mph at a push. But they are a lot less efficient for longer trips. You don't get roundabouts on motorways or big dual carriageways. Slip roads and grade-separated junctions - often grade-separated roundabouts - are more efficient for time.
Grade separated junctions also take up a lot of space and divide communities, so I'm not 100% in favour.
- NeedMoreTea 8y agoNot true. Motorway exits are normally a roundabout, with busiest exit slip roads traffic light controlled. Sometimes the roundabout is broken up with more extensive lights. A defining characteristic of motorways is the absence of junctions on the actual motorway. Dual carriageways sometimes adopt a motorway approach, with traffic light controlled slips, but are mainly roundabouts for junctions. It's been a while, but even on the A1, outside the A1M bits.
- barrkel 8y agoIt is not true that motorways go straight into roundabouts. They normally use sliproads to grade separated roundabouts.
- NeedMoreTea 8y agoThere's a slip road on and off the motorway and a roundabout at the end of motorway restrictions. That is straight into a roundabout. There are no junctions on motorways themselves. That was the whole point.