PHIL Shepherdson queries (Letters December 26) the reason why three No 6 buses arrived at once at his stop.

Unlike railways with their dedicated tracks, and some cities with segregated busways, York’s buses must share much of the highway network with other users.

If a bus is delayed, a gap occurs in the service. It will spend more time picking up passengers at each subsequent stop, and fall still farther behind. Following buses may then catch it up.

Such bus “bunching” can be reduced by priority measures such as bus lanes, bus gates and bus priority at traffic signals.

York is increasingly using technology that detects buses on the approaches to traffic signals and gives them priority. Real-time departures can be shown at stops and via hand-held internet devices.

But we are still caught in a vicious circle. Greater bus reliability would encourage more commuters to switch from cars.

But greater bus reliabilty will only come with reduced peak car use, and wider public acceptance of York’s need for bus priority measures.

Read more about York’s Quality Bus Partnership at

Paul Hepworth, Windmill Rise, York.