Introduce a stupid 45mph speed limit on drivers for 1 year after they've passed their test in NI. That means I could be on a motorway or big A road where people are going 70+mph, and be supposed to do 45mph.

Of course I don't do that unless I see a car that I think is a police car. I've been flashed at before for doing 45mph and find it way easier to drive at the same speed as other cars.

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Speed is absolutely a problem because it reduces the time you have to react to oncoming and crossing traffic and because it increases the impact of collisions.