When part-time traffic lights switch on, what signal do they display? Red would lead to panic braking, green in all directions would invite an accident. So what do they do to avoid chaos?
鈥� By eliminating red or green as unsafe, you already have the answer. The only remaining colour, yellow (or amber as it more usually known), is indeed what full and part-time UK traffic signals are programmed to display when they are switched on and when they resume operation after a power cut or other failure. Three seconds of amber is followed by a short period of 鈥渁ll red鈥� before the signals revert to normal operation, all traffic having been brought to rest safely.
Simon Morgan, Northwood, Middlesex, UK
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鈥� A more interesting question is what happens at relatively busy junctions where part-time traffic lights have been switched off? Who has right of way?
In the town centre closest to my house there are two crossroads where the traffic lights almost never function as traffic lights 鈥� they just flash amber.
Here in France the rule is 鈥減riorit茅 脿 droite鈥� (priority to the right), but an alternative rule 鈥渉e who arrives first, goes first鈥� is often applied by drivers. The latter puts a great deal of randomness into the equation. You need to decide how fast other cars are going and how likely they are to stop. Drivers become accustomed to making instant judgements along the lines of 鈥淚s he bigger than me?鈥� and 鈥淚s his car worth more, or less, than mine?鈥�. Battered white vans and buses always have right of way, unless you鈥檙e in a particularly bad mood.
鈥淗ere in France the rule is 鈥榩riority to the right鈥�, but 鈥榟e who arrives first, goes first鈥� is often applied鈥�
Occasionally the passage of a vehicle infringing the 鈥減riorit茅 脿 droite鈥� rule is accompanied by frenzied hooting, but you tend not to find that all the traffic has ground to a halt while the combatants sort it out.
The entertainment value of these junctions is much increased on Thursdays when a market occupies the car park between the two crossroads, invariably meaning that vans, left wherever the driver felt most convenient, obscure the lines of sight, including those to the pedestrian crossings.
Astonishingly, in the 19 years I have lived here, I have never heard of an accident.
Perhaps when you know that you can hit someone at any moment you slow down and take care. Perhaps, to drivers, a green light signalling 鈥渕ove鈥� negates any need to look. Has anyone done any comparative safety studies?
Halina Stanley, Revel, France