Huntingdon Road, the A1307, is one of the main roads into (and out of) Cambridge. It's not surprising, then, that it has a few unusual bits of traffic regulation.
For most of its length within the city boundary, Huntingdon Road has cycle lanes along both sides. These pre-date the appearance of such things in the Traffic Signs Regulations, and so the road markings and signs are specially authorised by the Secretary of State (reference GT46/16/02, dated 8th February 1980). The cycle lane restrictions are imposed by the City of Cambridge Area A (Consolidation) Order 1993 and the City of Cambridge Area H (Consolidation) Order 1993.
Towards the south-east end of the road, the cycle lane appears to run outside various parking bays. This arrangement isn't recommended by the Traffic Signs Manual, and at first glance it would seem to make the parking bays inaccessible to motor traffic. The traffic regulation orders, though, only ban traffic from cycle lanes, and define a cycle lane to be an area bounded by the kerb line and diagram 1049 placed 1.5m from the kerb line. Alongside the parking bays, the line is much further from the kerb line than this, so the cycle lane restrictions don't apply. Normally, the lack of restrictions would make the use of diagram 1049 here unlawful (direction 7 TSGD), but the authorisation for its use on Huntingdon Road doesn't require any such statutory prohibition to be in force.
There are several bus stops on Huntingdon Road, each marked with a road marking to diagram 1025. These became unlawful on 1st January 2007 (reg 3(2)(b) TSR) and should have been removed or replaced by bus stop clearway markings to diagram 1025.1.
Between its junctions with Sherlock Road and Storey's Way, Huntingdon Road is crossed by a toucan crossing. The sections of pavement connecing the crossing to the side have been surfaced in red, with tactile paving separating them from the rest of the pavement, but all of the poles where one might expect signs to diagram 956 are empty. Most sections of shared-use pavement in Cambridge are mentioned in traffic regulation orders (since this is necessary in order to make it an offence to drive on them, and hence to use signs to diagram 956), but these are not. This suggests that these sections of pavement may not be shared-use after all.
Towards the south-east end of the road, there are signs indicating a controlled parking zone. There should be two signs at each entrance to the zone, one on each side of the carriagway, but only one is provided at each end. In any case, the area isn't really a CPZ, since that requires that roads in the zone be marked with single or double yellow lines, or with "no loading" kerb markings, except in parking bays. The whole of the south-west side of this part of Huntingdon Road is a cycle lane and has no such markings (and mostly has no TRO restricting waiting either).
The sign to diagram 958.1 (with-flow cycle lane ahead) at the resumption of the south-east-bound mandatory cycle lane between Marion Close and Oxford Road should be diagram 959.1 (with-flow cycle lane) instead.
The speed limit signs just north-west of Sherlock Road are under-lit. All four signs should be lit (TSR Schedule 17 item 10), but only the ones on the north-east side of Huntingdon Road are.