Roads (width, speed and accommodating cycling)

Carriageway width

A clear layout and hierarchy of streets and other routes helps people to find their way around so that journeys are easy to make. Developments should contain a clear layout and hierarchy of streets.

The width of carriageways should be appropriate to their context. In residential developments, narrower streets are more suitable where there is limited vehicle movement and speeds are low. A design code may categorise the streets in a network as different street types.

For residential streets, a maximum design speed of 20mph should normally be an objective. The width of the carriageway and width of the kerb radii at side roads can have a significant influence on vehicular speeds. Where motor traffic flows are light and speeds are low, most cyclists are likely to be able to cycle on-carriageway in mixed traffic.

Residential and minor streets are an important part of an active travel network as they are used less by vehicles thought they provide a less direct active travel route when compared to busier roads.

Wider roads should be reserved for streets with higher levels of traffic and to accommodate public transport.

Cycling and carriageway widths

Manual for Streets illustrates the types of vehicles that different carriageway widths can accommodate. This needs to have regard to the primary and secondary riding positions of cyclists. Where no separation is provided and cyclists are expected to ride within the carriageway unprotected, lane widths between 3.25m and 3.9m should be avoided. Within this critical width, drivers are likely to attempt to overtake a cyclist resulting in a close pass.

Cycle lanes do not provide any physical protection and are therefore unlikely to be appropriate except where traffic speed and volume is very low.. However, they have a psychological traffic-calming effect by visually narrowing the carriageway, further helping to reduce speeds.

Cycle Infrastructure Design (LTN 1/20) provides more detailed guidance on road widths to accommodate cycling.

Other highway design considerations

An excessively regulated road environment (such as extensive central hatching, guard railing, or heavy reliance on road markings to dictate driver behaviour) can promote higher speeds and more aggressive driving tendencies. Highway designs should foster courteous behaviour, negotiation, and forgiveness, particularly on roads with lower traffic volumes.

Additional resources

Advice on providing for cycling in mixed traffic streets in Cycle Infrastructure Design (LTN 1/20)

Section 7 of Cycle Infrastructure Design (LTN 1/20) provides technical advice on acceptable minimum widths to enable safe cycling, as well as considering speed and volume of traffic.

Cycle Infrastructure Design (LTN 1/20)

Street dimensions in Manual for Streets

Section 7.2 of Manual for Streets includes advice on street dimensions, including carriageway widths.

Manual for Streets

Street hierarchy in the National Model Design Code

The National Model Design Code, in part 2 Section M.1, provides advice on how design codes can include a clear hierarchy of streets which respond to their context.

National Model Design Code

Movement in National Design Guide

Page 23 of the National Design Guide looks at how well-designed developments include a connected network of routes for all modes of transport.

National Design Guide

Streets and spaces in Active Design

Principle 6 of Active Design by Sport England discusses high quality streets and spaces.

Active Design

Street typologies in the Essex Design Guide

The Essex Design Guide provides eight illustrated examples of street typologies, reflecting their different role and function.

Essex Design Guide

ATE route check tool

In the ATE route check tool, SA03 assesses the effect of lane widths on conflict between cyclists and motor traffic. SP10 assesses the impact of street layout on user behaviour.

ATE route check tool