Bicycle lane in Washington, DC. 

Source: Alex Baca, Washington Area 

Bicyclist Association.

FHWA-SA-21-051

Bicycle Lanes

Most fatal and serious injury bicyclist crashes occur at non-intersection locations. 

Nearly one-third of these crashes occur when motorists are overtaking bicyclists1

because the speed and size differential between vehicles and bicycles can lead 

to severe injury. Many people are not comfortable riding a bicycle because of 

their fear that this type of crash may occur. To make bicycling safer and more 

comfortable for most types of bicyclists, State and local agencies should consider 

installing bicycle lanes. Providing bicycle facilities can mitigate or prevent 

interactions, conflicts, and crashes between bicyclists and motor vehicles, and 

create a network of safer roadways for bicycling. Bicycle Lanes align with the 

Safe System Approach principle of recognizing human vulnerability—where 

separating users in space can enhance safety for all road users.

Applications

The FHWA’s Bikeway Selection Guide

and Incorporating On-Road Bicycle 

Networks into Resurfacing Projects

assist agencies in determining which 

facilities provide the most benefit in 

various contexts. Bicycle lanes can be 

included on new roadways or created 

on existing roads by reallocating 

space in the right-of-way through 

Road Diets. Separated bicycle lanes, 

which use vertical elements—such 

as flexible delineator posts, curbs, or 

vegetation—between the bicycle 

lane and motorized traffic lanes 

provide additional safety benefits.2,3

For a marked bike lane without vertical 

elements, a lateral offset with marked 

buffer can help to further separate 

bicyclists from vehicle traffic. 

Considerations 

• In order to maximize a roadway’s

suitability for riders of all ages

and abilities, bicycle lane design

should vary according to roadway

characteristics (number of lanes,

motor vehicle and truck volumes,

speed, presence of transit), user needs

(current and forecasted ridership,

types of bicycles and micromobility

devices in use within the community,

role within the bicycling network), and

land-use context (adjacent land uses,

types and intensity of conflicting uses,

demands from other users for curbside

access). Separated bicycle lanes are

recommended on roadways with

higher vehicle volumes and speeds,

such as arterials.

• City and State policies may require

minimum bicycle lane widths,

although desirable bicycle lane widths

can differ by agency and functional 

classification of the road, current 

and forecasted bicycle volumes, 

and contextual attributes such as 

topography.

• Studies have found that roadways did

not experience an increase in crashes

or congestion when travel lane widths

were decreased to add a bicycle

lane.4

• Studies and experience in U.S. cities

show that bicycle lanes increase

ridership and may help jurisdictions

better manage roadway capacity.

• In rural areas, rumble strips can

negatively impact bicyclists’ ability to

ride if not properly installed. Agencies

should consider the dimensions,

placement, and offset of rumble strips

when adding a bicycle lane.5

• Bicycle lanes should be considered on

roadways where adjacent land use

suggests that trips could be served by

varied modes, particularly to meet the

safety and travel needs of low-income

populations likely to use bicycles to

reach essential destinations.6

49%

for total crashes on urban 

4-lane undivided collectors

and local roads.7

Bicycle Lane Additions can 

reduce crashes up to:

30%

for total crashes on urban 

2-lane undivided collectors

and local roads.7

For more information on this 

and other FHWA Proven Safety 

Countermeasures, please visit 

https://highways.dot.gov/ 

safety/proven-safety-counter 

measures and https://high 

ways.dot.gov/sites/fhwa.dot.

gov/files/2022-07/ 

fhwasa18077.pdf.

Safety Benefits:

1 Thomas et al. Bicyclist Crash Types on National, 

State, and Local Levels: A New Look. Transportation 

Research Record 673(6), 664-676, (2019). 

2 Separated Bike Lane Planning and Design Guide. 

FHWA-HEP-15-025, (2015).

3 (CMF ID: 11296) Developing CMFs for Separated 

Bicycle Lanes. FHWA-HRT-23-025, (2023).

4 Park and Abdel-Aty. Evaluation of safety 

effectiveness of multiple cross sectional features on 

urban arterials. Accident Analysis and Prevention, 

Vol. 92, pp. 245-255, (2016).

5 FHWA Tech Advisory Shoulder and Edge Line Rumble 

Strips, (2011).

6 Sandt et al. Pursuing Equity in Pedestrian and Bicycle 

Planning. FHWA, (2016).

7 (CMF ID: 10738, 10742) Development of Crash 

Modification Factors for Bicycle Lane Additions While 

Reducing Lane and Shoulder Widths. 

FHWA-HRT-21-012, (2021).

53%

for bicycle/vehicle crashes.3

Converting traditional or flush 

buffered bicycle lanes to a 

separated bicycle lane with 

flexible delineator posts can 

reduce crashes up to:

OFFICE OF SAFETY

Proven Safety 

Countermeasures