If site constraints necessitate narrower than normal streets, it is possible to use a type F street as a one-way street.

Around 100 dwellings can be directly served by a one-way street; otherwise it can be frustrating for residents at one end of such a street to have to make a long detour for a trip that could have been made more directly in the contra-flow direction.

For a one-way street, the width of the carriageway can be reduced to 3.7m. In every other respect the design requirements are as for the equivalent street type.

Where a one-way street leaves another street, no sight-lines are required, but where it joins another street, sight-line requirements are as they would be for the equivalent two-way street type. Side junctions onto a one-way street need a sight-line in the direction of oncoming traffic only.

In accordance with the Traffic Signs Manual, one-way streets should be clearly signed as such at their entry, exit and side junctions. Where there are long intervals between side junctions, there should be reminder signs for the benefit of drivers joining the street from frontage premises. These signs should be placed alternately on each side of the street at a minimum spacing of 100m between signs on the same side. Arrows should be painted on the street surface at 30m intervals.