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Local and Rural Road Safety Briefing Sheets

Access Management

(Driveways)

Introduction

Access points are essential elements of any roadway network as they represent the start and end points of any trip. 

Access points can range from large, complex intersections to simple, unpaved field entrances. For the purposes of this 

briefing sheet, the discussion of access management will center on basic driveways serving local and rural roads.

Every driveway represents potential conflict points between motor vehicles, pedestrians, and bicyclists. The number 

and complexity of these conflict points relate to the safety performance of the roadway. Therefore, access should be 

managed through thoughtful consideration of context, function, and location. Good access management begins at 

the planning level and proceeds through design, construction and ongoing maintenance. When well executed, access 

management will result in an appropriate balance between the safety and operating efficiency of the roadway and 

effective ingress and egress to adjacent properties.

Access management can accomplish the following:

• Preserve public investment in existing highway network;

• Address the safety of all users, and minimize the frequency and severity of related crashes;

• Improve access to adjacent properties; and

• Support economic goals within a community.

Road Access Permitting

The U.S. Supreme Court held that states should determine the access rights of abutting owners by their own laws and not 

by federal law.1

 As a result, there is considerable variation in how access permitting is accomplished. States and localities 

use administrative rules, access codes, guidelines, and design standards to establish driveway permit requirements and 

restrictions for driveway placement, design, and construction. Implementing these requirements through the driveway 

permitting process can affect the operation and safety of local and rural roads at driveway locations.2

 Among the 

considerations for reviewing and granting permits are context (e.g., speed and traffic volume); degree of access (e.g., full 

or partial, exclusive or redundant); geometry (e.g., physical location, grade, sight distance, turning radius); treatment of 

cyclists and pedestrians; and other considerations (e.g., parking, drainage, pavement type).

Context

For local and rural areas, characteristics of the surrounding roadway should be considered as the agency discusses the 

location and scale of the driveway with the property owner. A location sketch of the proposed or existing driveway 

would be beneficial towards discussing any modifications necessary. Other information may be needed to properly 

review the access point, such as: 

• Speed of the adjacent roadway;

• Volume and types of traffic on the roadway including cyclists, pedestrians, type and number of heavy vehicles;

• Spacing of existing driveways;

• Property lines of neighboring parcels; and

• Traffic impacts generated by the property.
Degree of Access 

Driveways can allow all movements or restrict various movements into and out from the entrance. Reasons for 

restricting movements include:

• Limited sight distance that does not allow adequate time to judge traffic;

• Reducing the number of conflicting movements to increase safety for all road users; and

• Close proximity to complex intersections; e.g., signalized, busy commercial entrances.

Geometry

Driveways should be located where highway 

alignment and grades are favorable. Driveways 

should not be located near sharp curves, steep 

grades, or points that unnecessarily interfere with 

the free and safe movement of traffic. In general, 

driveways should intersect the main roadway in a 

perpendicular fashion, and highly skewed layouts 

should be avoided whenever possible.

In rural areas, driveways obscured by sharp curves, 

steep hills, trees, and buildings limit sight distance 

available for drivers entering or leaving the roadway 

as well as drivers traveling on the roadway. Drivers 

entering the roadway from a driveway need a clear line of sight in each direction to identify approaching vehicles 

before entering the roadway. Additionally, drivers traveling on the roadway must be able to see vehicles entering the 

roadway in order to slow or even stop if necessary. Drivers slowing or stopping to leave the roadway at a driveway 

create a risk to following drivers who must slow, and possibly stop, as the lead vehicle turns onto the driveway. 

Surface Finish and Drainage

Driveway surfaces should be paved or stabilized to prevent driveway 

materials from washing onto the adjoining roadway. In addition, 

driveways should incorporate crowning, ditching, and culverts as 

needed to prevent the diversion of surface water onto the adjoining 

roadway. Crowning of the driveway directs water to driveway shoulders 

or edges into roadside ditches rather than directly onto the roadway 

surface. Drainage pipes or culverts that protrude above the ground or 

provide an opening into which a vehicle can drop and abruptly stop can 

be roadside hazards if not properly designed or shielded. To minimize 

the severity of roadway departure crashes, the ditch, pipe, or culvert 

should be re-contoured, extended, made traversable, or shielded.3

Protruding Drainage Pipe

Drainage Pipe Shielding
Sight Distance

Properly located and designed driveways allow drivers to see oncoming traffic clearly from the point where the 

driveway meets the roadway. A turnaround within the driveway is useful in providing vehicles an opportunity to 

avoid backing onto the roadway. Vegetation such as tree limbs and bushes along both the roadway and the driveway 

should be trimmed to maintain adequate visibility. The table below provides guidance on recommended sight 

distances. 

Suggested Sight Distances for Passenger Cars Entering Two Lane Roadways from Stop with Various Speed Limits

Operating Speed on Roadway 

(Mph)

Safe Sight Distance Looking Left 

from Driveway (ft.)

Safe Sight Distance Looking Right 

from Driveway (ft.)

20 225 195

30 335 290

40 445 385

50 555 480

60 665 575

Source: American Association of State Highway and Transportation Officials (AASHTO), A Policy on Geometric Design of 

Highways and Streets 2011 (AASHTO: Washington, DC, 2011).

Driveway Density

A high density of driveway entrances, as measured by driveways per mile, should be avoided to minimize traffic 

conflicts and construction costs. As discussed in the Highway Safety Manual, areas where effective access 

management has been implemented have experienced a 5-23 percent reduction in all crashes along two-lane rural 

highways.4

 Consolidating multiple, closely-spaced driveways should be considered when possible. A single, welldesigned and properly-controlled driveway with good traffic circulation within the site will function more safely and 

efficiently than several driveways to a parcel, and conflict points are reduced both on and off the public roadway. 

Other Considerations5

Other factors to consider include lighting and marking the driveway entrance. Lighting the driveway entrance may 

be helpful in some cases to illuminate vehicles entering the roadway as well as making the driveway more visible 

to traffic on the roadway. Additionally, the installation of delineators marking the driveway entrance could be 

appropriate to improve the visibility of driveway edge lines.
Resources

The resources listed below are available to local and rural roadway owners to assist in understanding the benefits of 

access management and to more safely and efficiently locate, design, and operate driveways.

Alabama Department of Transportation, Access Management Manual (2014). Available at: 

https://www.dot.state.al.us/maweb/doc/ALDOT%20Access%20Management%20Manual.pdf

Center for Urban Transportation Research, Land Development and Subdivision Regulations 

that Support Access Management, (n.d.). Available at:

http://www.cutr.usf.edu/research/land_dev.pdf

Federal Highway Administration, Technical Summary: Access Management in the Vicinity of 

Intersections, FHWA-SA-10-002 (Washington, DC: 2002). Available at:

http://safety.fhwa.dot.gov/intersection/resources/fhwasa10002/

Federal Highway Administration. “Proven Safety Countermeasures: Corridor Access 

Management,” FHWA-SA-12-006 (Washington, DC: 2012). Available at:

http://safety.fhwa.dot.gov/provencountermeasures/fhwa_sa_12_006.htm

Transportation Research Board (TRB), NCHRP Report 659: Guide for the Geometric Design of 

Driveways, National Cooperative Highway Research Program (Washington, DC: TRB, 2010).

Available at: http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_659.pdf

1

 Sauer v. City of New York, 206 U.S. 536, 548, 27 S.Ct. 686, 690, 51 L. Ed. 1176, 1907

2

 Transportation Research Board (TRB), NCHRP Synthesis 304: Driveway Regulations Practices, National Cooperative Highway 

Research Program (Washington, DC: TRB, 2002).

3

 AASHTO, Roadside Design Guide, (Washington, DC: AASHTO, 2012).

4

 Federal Highway Administration, “Proven Safety Countermeasures: Corridor Access Management,” FHWA-SA-12-006 

(Washington, DC: 2012). Available at: http://safety.fhwa.dot.gov/provencountermeasures/fhwa_sa_12_006.htm. 

5

 James C. Thomas, Rural Driveway Design (Texas A&M University: n.d.).

FHWA-SA-14-080