11.3 Cycling infrastructure design considerations
Protecting cyclists from motor traffic is essential. Unsafe roads are one of the most significant barriers to the uptake of cycling in the UK and the provision of protected cycle space normally results in an increase in cycling.
Safe routes can take cyclists on the carriageway, where traffic and speeds are suitably low, but on busier and faster roads some form of segregation is normally required.
As a guide, designers should seek to create cycle routes that would be safe for children to use without supervision.
The following table from LTN 1/20 shows the appropriate level of protection required based on traffic volumes and speed limits.
Designers are encouraged to exceed the minimum requirements, particular the level of traffic at which on street cycling becomes ‘suitable for most people’. This is set at 5000 PCUs (passenger car equivalent units) per day for 20mph streets, but designers should aim for separation on all streets above 2000 PCU/day which is in line with international best practice [Reference 49].
Figure 11-1: Appropriate cycle infrastructure by traffic speed and volume (Credit - LTN 1/20).
Appropriate protection can be provided by using the following cycle route typologies. In most cases, these will be integrated into the design of the street and as such detailed guidance is provided in the street typologies guidance in this document.
Motor traffic free cycle path. These include routes on disused railway lines, through parks and public open space, on canal and riverside towpaths, and public rights of way.
These can form long distance, inter urban routes, or short routes within urban areas. Where cycle and/or pedestrian volumes are sufficiently high, separation may be required.
Segregated cycle track - This refers to routes that are within the highway but are separate from motor traffic. There are generally three levels of segregation:
- Full height kerb – Normally at carriageway level, with full height kerb separation on both sides, and some buffer space between the track and the carriageway. This should normally be avoided, and stepped cycle tracks are preferred.
- Stepped cycle track - Set between pavement level and carriageway level, separated by low kerbs. This is the preferred method of segregation for new streets in Surrey.
- Pavement level cycle track – Set at pavement level, separated by a raised strip to clearly mark the track, and constructed in a different surfacing material. Line markings are not appropriate as separation.
Cycle lanes – Areas of the carriageway reserved for cyclists, as defined by Traffic Signs Regulations and General Directions (TSRGD). Either demarked by a solid white line (mandatory lane) or a dashed white line (advisory).
Cycle lanes with light segregation - Describes the use of intermittent physical features placed along the inside edge of a mandatory cycle lane to provide additional protection from motor traffic. This can give a greater perception of safety, which is important in encouraging people to cycle, whilst allowing permeability.
On street – Where traffic flows and speeds are low (<20mph), and streets and junctions are well designed, on street cycling can be safe and attractive. LTN 1 / 20 recommends that streets should be suitable for Bikeability Level 2 skills, meaning that they could be used independently by a 12-year-old child.
Continuous level surface streets - Level surface streets have no, or only a slight, kerb upstand, removing vehicle priority. These typically have pedestrian priority, and very low traffic levels.
Figure 11-2a: Streets must be designed so that they are safe for cyclists. Chapeltown, Aberdeenshire. (Credit - Andy Cameron)
Figure 11-2b: Streets must be designed so that they are safe for cyclists. Poundbury, Dorset. (Credit - Andy Cameron)
The following table sets out suggested segregation methods based on the street typologies in this guide. The cycle track widths are recommended minimums and wider tracks may be required where there are likely to be high flows of cycle traffic, typically over 200 per hour. Refer to LTN 1/20 for further guidance.
Table 11-1. Appropriate cycle segregation by street type
| 1. Primary Streets a) Link Roads / Bypasses | Motor traffic free cycle path |
|---|---|
| 1. Primary Streets a) Link Roads / Bypasses | Segregated cycle track – full height kerb |
| 1. Primary Streets b) Avenues | Segregated cycle track – stepped |
| 2. High Streets a) High Activity / Arterial | Segregated cycle track – stepped |
| 2. High Streets a) High Activity / Arterial | Light segregation |
| 2. High Streets b) Low Traffic | On street cycling |
| 2. High Streets b) Low Traffic | Light segregation |
| 2. High Streets c) Traffic Free | N/A |
| 3. Secondary Streets / Local High Streets | On street cycling |
| 3. Secondary Streets / Local High Streets | Segregated cycle track - stepped |
| 3. Secondary Streets / Local High Streets | Light segregation |
| 4. Local Streets | On street cycling |
| 5. Tertiary Streets a) Shopping Mews / Courts | N/A |
| 5. Tertiary Streets b) Residential Mews / Back Streets | On street cycling (level surface) |
| 5. Tertiary Streets c) Rural Lanes | Motor traffic free cycle path |
| 5. Tertiary Streets c) Rural Lanes | On street cycling |
| 1. Primary Streets a) Link Roads / Bypasses | Alternative route recommended, avoiding junctions |
|---|---|
| 1. Primary Streets a) Link Roads / Bypasses | At least 2 separation from carriageway2.2 metre wide, full height (100 -125mm) kerbs |
| 1. Primary Streets b) Avenues | 2 metre wide, stepped cycle track with 50 – 65mm shallow splayed kerb.To include 0.5 metre wide buffer strip alongside parking. |
| 2. High Streets a) High Activity / Arterial | 2 metre wide, stepped cycle track with 50 – 65mm shallow splayed kerb.To include 0.5 metre wide buffer strip alongside parking. |
| 2. High Streets a) High Activity / Arterial | Cycle lane at carriageway level. Use of trees, planters or bollards to provide segregation. |
| 2. High Streets b) Low Traffic | Speeds must be 20mph or lower. |
| 2. High Streets b) Low Traffic | Cycle lane at carriageway level. Use of trees, planters or bollards to provide segregation. |
| 2. High Streets c) Traffic Free | N/A |
| 3. Secondary Streets / Local High Streets | Speeds must be 20mph or lower, and traffic flows should be low with no bus and limited HGV traffic. Otherwise use a segregated cycle track (stepped or light segregation). |
| 3. Secondary Streets / Local High Streets | 2 metre wide, stepped cycle track with 50 – 65mm shallow splayed kerb.To include 0.5 metre wide buffer strip alongside parking. |
| 3. Secondary Streets / Local High Streets | Cycle lane at carriageway level. Use of trees, planters or bollards to provide segregation. |
| 4. Local streets | Speeds must be 20mph or lower.Modal filtering encouraged. |
| 5. Tertiary Streets a) Shopping Mews / Courts | N/A |
| 5. Tertiary Streets b) Residential Mews / Back Streets | Design speeds must be very low. |
| 5. Tertiary Streets c) Rural Lanes | Alternative routes recommended |
| 5. Tertiary Streets c) Rural Lanes | Only suitable if speeds are kept low and traffic volumes are low |
References
- Reference 49: Based on the Dutch CROW Design Manual for Bicycle Traffic, as referenced in: London Cycling Campaign (2019) Infrastructure Handbook (Return to content for reference 49).