In 1991 the Department of Transport published Local Transport Note 1/91: Keeping Buses Moving. This set out the full range of bus priority measures which highway authorities were encouraged to adopt.
Separate chapters covered with-flow bus lanes, contraflow bus lanes and bus-only streets (which included bus gates). The first two were the measures for which the Department had been providing signage; the third was what highway authorities had been doing off their own bat using “No Entry” signs with “Except buses” plates.
As bus lanes were measures which the Department had been advocating for years and for which recommended practice had been set out in the Traffic Signs Manual, LTN 1/91 largely repeated established practice.
Its chapter about bus-only streets was more interesting. Not only did it survey existing practice (see Bus Gates), it introduced new signs which highway authorities could use. For the first time, these made it possible for highway authorities to allow cycles to use schemes which had until then been strictly bus-only. Until the new version of TSRGD was issued in 1994, local authorities did, however, need to submit their schemes to the Department and obtain permission to use the new signs.
The signs which were made available are shown below:
Of these the most significant was the blue roundel with a bus and a cycle (later diagram 953). This was, in effect, the answer to the missing “Except buses and cycles” plate for a No Entry sign.
The pedestrian zone signs could be used to prohibit all through traffic except buses and cycles but still allow vehicles access to local premises. A bus gate could be placed at one end of a section of road between two junctions with the rest of the section made a pedestrian zone.
These signs became generally available as part of TSRGD 1994.
LTN 1/91 was updated and reissued as LTN 1/97.