The restrictions on Camrose Avenue are unique. They are the result of a failed experiment in 1974-75 to try to stop HGVs from using Camrose Avenue as a cut-through to and from the M1. This was to be achieved by imposing a width restriction.
As Camrose Avenue was a bus route and buses are the same width as HGVs, bypasses were created around the width restrictions which only buses could use. Gates were to be installed which would open while the bus was sitting at the adjacent bus stop.
This was Harrow's first attempt at combining width restrictions with bus bypasses. They tried again in 1976 on Headstone Lane, with a configuration which worked better and was repeated elsewhere, albeit with only occasional use of the bypass by refuse and emergency vehicles.
This aerial view shows the current layout (North is at the top):
Here is a closer view:
Eastbound traffic is split by the traffic island ringed in red: the bus gate to the left; the width restriction to the right. Westbound traffic is split likewise by the traffic island ringed in yellow. Eastbound and westbound traffic are separated by a snake-like object, the central median strip. This carries a post-and-rail barrier to stop eastbound and westbound traffic crashing into each other (the image is from 2008; the signs have since been updated and the barrier has lost all it chevrons):
You can see how the restrictions appear when approached from each direction in Eastbound Approach and Westbound Approach.
If you have received a PCN on Camrose Avenue, the following pages are relevant:
and, depending on where you were:
Background material which is referenced includes:
Written 31st October 2025; last updated 15th February 2026