Sir - Margaret Pargeter's objections to removing London and airport coaches from city streets (Letters, July 18) are easily resolved in the following way. These services could begin their journeys at the Pear Tree park-and-ride and call in at Thornhill park-and-ride to pick up further passengers. During daytime hours, coaches would take the A40 northern bypass from Pear Tree to Thornhill, and intending passengers from Oxford would connect using existing 300 or 400 bus services.

Coach tickets could be purchased on these buses and transit from city centre to either park-and-ride would be free on presentation of a valid coach ticket; coaches would not depart until the connecting bus had arrived (and vice-versa for incoming coaches). At times of day or night when no 300 and 400 services operate, congestion and air pollution are minimal, so coaches could be routed through the city centre to collect or drop passengers with little detriment to other traffic or to air quality. Such a scheme would offer many advantages.

It would liberate slots at Gloucester Green, permit only low-emission park-and-ride buses to operate within the ring road during peak hours, eliminate the bulk of coach movements up and down High Street when congestion and air pollution are worst, cut wear on city roads, and improve access for those city residents who do not live in St Clements or Headington, as well as for passengers connecting from outside the city.

For the scheme to operate efficiently, a coach terminus would need to be built at Pear Tree, and a new coach-only lane on the eastbound approach to the Green Road roundabout might be necessary to minimise commuter delays.

Robin Gill, Headington