I was watching a European police chase show the other day. It showed people trying to back up on “sliproads” and they kept spinning out. And the commentary went something like, “Anyone who has ever tried to back up or turn around on a sliproad will know how difficult of a task this is.”
So, what are sliproads? I know they come off/merge to the main highway like exits, but what makes them different? I get the impression that it is only possible to drive one way on them, making it less likely that someone will go the wrong way.
Sorry, just realised I haven’t really answered your question; they generally feed into the main road at a very shallow angle, making a right turn (the wrong way) against the traffic flow very difficult or impossible.
Thanks, Mangetout! I understand what you are talking about. I just didn’t quite understand what they were because on TV it showed the cars spinning out whenever they tried to back up on the sliproads.
Yes, it would be quite difficult for many drivers to reverse back along them:
-they usually slope up or down (depending on whether the motorway they are joining passes over or below the minor road)
-they typically curve along their length (as the minor road typically crosses the motorway at right angles)
-they are quite long, often several hundred yards or more
-they are one-way and other traffic moving along them tends to be building up speed (at least in the case of an entry slip road)
These factors would make reversing an unfamiliar and dangerous task.
One reason that speeders, or chasees spin out on sliproads is that you are supposed to be slowing down from the high speed road to join regular urban traffic.
The perception of speed on big roads is less and folk simply forget to slow down, many sliproads are designed with curves which force a reduction in speed.
Obviously someone being chased at 100mph + cares not a jot for this, they may reduce speed but never enough.
With off ramps you very often get a termination in a roundabout, something you might not be familiar with, its just a small circular bit of road into which other roads terminate and exit, you can only go one way on these things, but what it also usually means is that as you reach the roundadout, you may well have to stop to allow other traffic to pass in front of you, and also you will have to make a 90 degree turn.
Approaching one of these at high speed is not a good idea.