Panda crossing

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The panda crossing was a type of signal-controlled pedestrian crossing used in the United Kingdom from 1962 to 1967.

[edit] Background

In the early 1960s, the British Ministry of Transport, headed by Ernest Marples, was looking for a way to make pedestrian crossings safer under increasingly heavy traffic conditions. The successful zebra crossing design was not considered safe enough for busy roads and could create traffic delays as pedestrians crossed whenever they wanted. Off-the-shelf light-controlled systems were available but were too expensive for widespread use. Some cities had innovated their own one-off crossings but the lack of standardisation was considered a safety issue. Furthermore, all existing signalled crossings tended to have two major drawbacks: stopping traffic for long periods of time and violating contemporary right-of-way law by signalling "Don't cross" to pedestrians.

The panda crossing was introduced in 1962 as an attempt to combine the best features of available and experimental crossing systems. The first public example was opened on 2 April of that year outside Waterloo Station, London. The majority of the initial sites used for this experiment were in Guildford where all 13 existing crossings were converted, and in Lincoln where 10 crossings were converted. Further sites across England and Wales increased the size of the experiment to more than forty sites in all.

[edit] Design and operation

The Panda's distincive two-light signal head with striped Belisha beacon (the "STOP" text on the red light persisted through to early Pelican crossings)

The layout was superficially similar to a traditional zebra crossing, with a painted area on the road announced by Belisha beacons. For distinction, the panda road pattern was different (triangles rather than stripes) and the beacons were striped, not plain. The main additions were the light signals on the beacon poles. The traffic signals consisted of a pair of lamps, red and amber, while the pedestrians had a single signal displaying the word "Cross" when appropriate.

In the idle state, all the crossing's lights were off. A pedestrian wanting to cross would press a button on the beacon pole and be instructed to wait by an illuminated sign near the button. The system allowed for a pause between crossings in order to avoid traffic delays and so the pedestrian might wait a short while before anything happened. The amber traffic light would pulsate for a few seconds to inform motorists that someone was about to cross; a pulsating red light was then the signal to stop. At this point, the pedestrians' "Cross" signal began to flash. After a few seconds, the "Cross" light started to flash faster and the pulsating red traffic light was changed to a flashing amber (this "flashing" phase was considered distinct from the initial "pulsating" amber light). The "Cross" light flashed increasingly fast as crossing time ran out, and the traffic was allowed to proceed during the flashing amber phase if the crossing was clear. Eventually, the "Cross" light and the amber switched off completely and the crossing was reset.

The panda crossing deliberately omitted any sort of "Don't cross" message for pedestrians in order to avoid breaching the aforementioned right-of-way laws. The measured pause between crossings helped to keep traffic flowing. The light sequence also prevented long delays by allowing traffic to move after a few seconds if nobody was crossing. However, despite its apparent rationality, the design was not a success. In particular, the distinction between the flashing and pulsating amber phases was subtle yet highly significant and there was no clear "Go" signal at the end of the sequence.

[edit] Successors

By 1967, the panda crossing was a matter of concern for the Ministry of Transport, and so a new type of crossing, the X-way, was introduced. Surprisingly, the new system was not phased in gradually by replacement, rather the pandas were removed seemingly as a matter of urgency. The X-way itself soon disappeared when, in 1969, the modern Pelican crossing was introduced.

[edit] References

• BBC news report 2 April 1962, on the introduction of Panda crossings, and subsequent developments (with video of Marples's first crossing).
• "Hairbrained and most dangerous" - the history of pedestrian crossings at Chris's British Road Directory
• Panda Crossings: operation and signals - leaflet produced by the Ministry of Transport via the Central Office of Information