Technical Summary 

Access Management in 

the Vicinity of Intersections 

FHWA-SA-10-002 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Foreword 

This technical summary is designed as a reference for State and local transportation officials, Federal Highway 

Administration (FHWA) Division Safety Engineers, and other professionals involved in the design, selection, 

and implementation of access management near traditional intersections (e.g., signalized, unsignalized and 

stop controlled intersections). Its purpose is to provide an overview of safety considerations in the design, 

implementation, and management of driveways near traditional intersections in urban, suburban, and rural 

environments where design considerations can vary as a function of land uses, travel speeds, volumes of traffic 

by mode (e.g., car, pedestrian, or bicycle), and many other variables. 

The technical summary does not include any discussion on roundabout intersections. More information 

about roundabouts is available in Roundabouts: An Informational Guide, published by the FHWA [1]. Section 1 

of this technical summary presents an overview of access management factors that should be considered for 

improving safety near intersections in any setting. Section 2 presents access management considerations and 

treatments to improve safety near traditional intersections in suburban, urban, and rural settings. This section 

features a case study of an access management retrofit project in a suburban area. Section 3 points the reader to 

additional resources. 

This publication does not supersede any publication; and is a Final version. 

Disclaimer and Quality Assurance Statement 

Notice 

This document is disseminated under the sponsorship of the U.S. Department 

of Transportation in the interest of information exchange. The U.S. Government 

assumes no liability for the use of the information contained in this document. 

Quality Assurance Statement 

The Federal Highway Administration (FHWA) provides high-quality information 

to serve Government, industry, and the public in a manner that promotes 

public understanding. Standards and policies are used to ensure and maximize 

the quality, objectivity, utility, and integrity of its information. FHWA periodically 

reviews quality issues and adjusts its programs and processes to ensure 

continuous quality improvement. 
 

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Contents 

Introduction 1.

Section 1: General.Access.Management 

Considerations. 2.

1.1 Locate Driveways on the Appropriate 

Roadway Functional Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

1.2 Limiting Driveways within the Functional Area 

of an Intersection Improves Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

1.3 Reducing the Number and Types of Conflict Points 

Created by a Driveway May Reduce Crashes . . . . . . . . . . . . . . . . . . . . . . . . 3 

1.4 Eliminating Left-Turn Movements at Driveways 

is Beneficial from a Safety Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

1.5 Median Treatments Can Impact Safety . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

1.6 Reducing Driveway Density Reduces Crash Rates. . . . . . . . . . . . . . . . . . . . 5 

1.7 Properly Designed Driveways Influence Safety 

and Mobility at the Driveway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

Section 2: Special.Considerations.for.Suburban, 

Urban.and.Rural.Areas. 7.

2.1. Access Management Considerations 

in the Vicinity of Suburban Intersections . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

2.2 Access Management Considerations 

in the Vicinity of Urban Intersections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

2.3 Access Management Considerations 

in the Vicinity of Rural Intersections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Section 3: References. 14.

Cover Photo by Ralph Bentley 

FHWA | Access Management in the Vicinity of Intersections iii 
iv FHWA | Access Management in the Vicinity of Intersections 
 

 

 

 

 

 

 

 

Introduction 

“Access management” refers to the design, implementation and management of entry and exit 

points (i.e., driveways, entrances or exits) between roadways and adjacent properties. These entry 

and exit points can be managed by careful planning regarding their location, the types of turning 

movements allowed, and if appropriate, medians that provide or prohibit access to the driveways. 

Developing and implementing effective access management strategies that promote or improve 

safety requires considering the location of driveways in the context of current and future access 

needs, current and future intersection operations, and mobility for pedestrians and bicyclists. 

This technical summary is designed as a reference for 

State and local transportation officials, Federal Highway 

Administration (FHWA) Division Safety Engineers, and 

other professionals involved in the design, selection, and 

implementation of access management near traditional 

intersections (e.g., signalized, unsignalized and stopcontrolled intersections). Its purpose is to provide 

an overview of safety considerations in the design, 

implementation, and management of driveways near 

traditional intersections in urban, suburban, and rural 

environments where design considerations can vary as a 

function of land uses, travel speeds, volumes of traffic by 

mode (e.g., car, pedestrian, or bicycle), and many other 

variables. The technical summary does not include any 

discussion on roundabout intersections. More information 

about roundabouts is available in Roundabouts: An 

Informational Guide, published by the FHWA [1]. 

Section 1 of this technical summary presents an overview 

of access management factors that should be considered 

for improving safety near intersections in any setting. 

Section 2 presents access management considerations 

and treatments to improve safety near traditional 

intersections in suburban, urban, and rural settings. This 

section features a case study of an access management 

retrofit project in a suburban area. Section 3 provides 

references. 

Photo: Ralph Bentley (used with permission) 

FHWA | Access Management in the Vicinity of Intersections 1 
2 FHWA | Access Management in the Vicinity of Intersections

Providing access (i.e., driveways, entrances or exits) onto 

roadways with the lowest traffic volumes and speeds 

generally improves safety near intersections. In planning, 

designing, and managing access, critical consideration 

must be given to arterial and collector streets as these 

streets serve both mobility and access functions. To the 

extent possible, it is best to manage driveways so that 

access is provided to and from the roadway with the 

lower functional classification as these roadways typically 

have lower traffic volumes and speeds. This helps to 

reduce the frequency of conflicts, which minimizes both 

the opportunity for crashes and the severity of those 

crashes, should they occur. 

Section 1: General Access Management Considerations

Planning, designing, and implementing access management strategies to promote safety near intersections begins with an awareness of several considerations. These considerations are independent 

of the environment or setting in which the driveway is located (i.e., urban, suburban, or rural). These 

factors include roadway functional classification (sometimes referred to as “roadway hierarchy” 1 ); 

the functional area of the intersection; the location and number of driveways and resulting conflict 

points; the use of medians; and driveway design. 

By considering the following seven guidelines when developing and evaluating access management 

treatments, practitioners can apply access management techniques to help improve safety in the 

vicinity of intersections2.

DOWNSTREAM UPSTREAM

UPSTREAM DOWNSTREAM

Physical Area of Intersection

Functional Area of Intersection

Figure 1: Functional and Physical Areas of an Intersection

1 Typical roadway functional classifications include freeway, arterial, collector, and local street—with freeways providing the highest level of 

mobility but the lowest level of accessibility, and local streets providing the highest level of accessibility but lowest level of mobility (assuming 

normal traffic).

2 These are general guidelines and may not apply to all situations. Understanding these principles can help practitioners more comprehensively 

evaluate options, understand tradeoffs, and make better decisions to help promote the safest possible access management treatments in the 

vicinity of intersections.

1.2 Limiting Driveways within the Functional Area of an Intersection Improves Safety

Figure 1 provides a schematic 

representation of functional and physical 

areas of an intersection. The physical 

area of an intersection is a fixed area that 

represents the space confined within the 

corners of the intersection. 

The functional area of an intersection 

includes areas upstream and downstream 

of the intersection. Unlike the physical 

area of an intersection, the functional 

area of an intersection is variable. The 

American Association of State Highway 

and Transportation Officials’ (AASHTO) A 

Policy On Geometric Design of Highways and 

Streets [2] defines the upstream functional 

1.1 Locate Driveways on the Appropriate Roadway Functional Classification
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

area of an intersection as a variable distance, influenced 

by: 1) distance traveled during perception-reaction time, 

2) deceleration distance while the driver maneuvers to a

stop, and 3) the amount of queuing at the intersection3.

The upstream functional area is highly dependent on

whether or not the traffic in the through lane is required

to come to a stop at the intersection. Therefore, the

functional area should be a consideration in situations

where a driveway is near an intersection (due to a traffic

signal or stop sign).

For example, at a stop-controlled intersection with 

approach speeds of 30 mph and a queue length of 

125 feet (with additional assumptions for perceptionreaction time and deceleration distance), the upstream 

functional area of the intersection is 200 feet. For a 

signalized intersection with identical speed and queue 

characteristics, the upstream functional area is 395 feet. 

At that same stop-controlled intersection with a similar 

queue but a higher approach speed – 50 mph – the 

upstream functional area is 425 feet (compared to 

just 200 feet with 30 mph approach speeds). For a 

signalized intersection with identical speed and queue 

characteristics, the upstream functional area is 735 

feet [3]. 

The AASHTO Policy on Geometric Design does not define 

the downstream functional area of the intersection as the 

criteria used to determine the downstream functional 

area can vary between jurisdictions. The Access 

Management Manual [3], published by the Transportation 

Research Board (TRB), notes that “stopping sight 

distance is one method for establishing the downstream 

functional distance of an intersection.” 

In the case of the stop-controlled intersection 

previously described (30 mph approach speed, 125 

feet queue), the downstream functional area using the 

Access Management Manual’s stopping sight distance 

calculation is 200 feet. At an approach speed of 50 

mph the downstream functional area is 425 feet. When 

calculating downstream functional area with this method, 

traffic control at the intersection is not a factor. 

Limiting or, where possible, eliminating driveways within 

the functional area of an intersection (upstream and 

downstream) helps reduce the number of decisions 

motorists must make while traveling through an 

intersection and improves safety in the vicinity of an 

intersection. A recent study evaluating crashes in the 

vicinity of signalized intersections in suburban areas 

completed by the Utah Department of Transportation [4] 

provides one illustration of the correlation between 

driveways in the functional area of intersections and 

increased safety risk. The study evaluated right-turn and 

rear-end crashes at signalized intersections in suburban 

areas. The study found that the existence of accesses 

within the upstream functional area of the intersection 

correlated to increased crashes and crash severity costs. 

The report identified an even greater increase in total 

crashes, crash rates, and rear-end crashes as commercial 

access density increased4

. 

Additionally, a recent study by the Texas Transportation 

Institute (TTI), the “Roadway Safety Design Synthesis” [5] 

discusses the safety effect of driveways in rural areas. 

The study includes equations to calculate the Accident 

Modification Factor (AMF) for access control based 

on the number of driveways within 250 feet of a rural 

intersection. 

1.3 Reducing the Number and Types of Conflict Points Created by a Driveway May 

Reduce Crashes 

In general, the number and types of conflict points 

(i.e., the number of locations where the travel paths 

of two different vehicles may cross) at the intersection 

of a driveway and a public road influence the safety 

of motorists. It is desirable to minimize the number 

of conflict points created with existing and future 

driveways since more conflict points increase the risk of 

a crash occurring. For example, a crash due to crossing 

maneuvers (created by motorists turning across the 

roadway or making left turns) can lead to more severe 

crashes then merging or diverging conflicts because of 

the angle and speed differentials between the vehicles. 

As the angle and speed differentials increases, crash 

severity can also increase. 

The number and type of conflict points at a driveway 

can be managed by limiting both the amount of access 

allowed at the driveway (e.g., full-movement, left-in/leftout, right-in/right-out, right-in only or right-out only) and 

3 American Association of State Highway and Transportation Officials, A Policy On Geometric Design of Highways and Streets, 5th Edition 

(Washington, DC: 2004). 

4 This study examined safety-related data upstream of signalized intersections within suburban areas. 

FHWA | Access Management in the Vicinity of Intersections 3 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the location of the driveway relative to other driveways in 

the area. In most cases, property owners prefer to have 

at least one direct, full-movement driveway from their 

property onto the major street (i.e., the street with higher 

traffic volumes) adjacent to the property. In many cases, 

it may occur that property owners are requesting direct, 

full-movement driveways to different properties on both 

sides of the major street. It is not always possible to 

align these driveways to minimize the number of conflict 

points, so another strategy, such as implementation of a 

raised median, should be considered (see Section 1.5 for 

information on median treatments). 

Figure 2 illustrates a scenario in which it is not possible 

to align the full-movement driveways in a manner that 

would reduce conflict points. Figure 3 illustrates how 

construction of a raised median on the major roadway 

could reduce the number of conflict points in this 

situation. The raised median in Figure 3 limits the access 

to Driveways A and B to right-in/right-out movements 

only. Also, the number of conflicts in the vicinity of 

Driveways C and D in Figure 2 are reduced by relocating 

Driveway C to the minor road (see Figure 3). This solution 

limits conflict points by providing a direct, full-movement 

driveway (i.e., left-in/left-out/right-in/right-out) to the 

minor road, and by constructing a median on the major 

road and limiting access at Driveway D to right-in/rightout only. 

Finally, in Figure 3, additional right-in/right-out only 

driveways are provided on the minor street (Driveways E 

and F) to improve the access to the properties adjacent to 

Driveways B and D. If possible, it is preferable to provide 

driveways onto the minor street instead of on the major 

street in order to preserve mobility on the major street. 

Limiting turn movements to properties adjacent to the 

roadway can result in circuitous travel to and from a site. 

For example, a motorist exiting Driveway B is limited to 

one direction of travel and is required to make a U-turn or 

use Driveway F to reach other destinations. 

MAJOR 

ROADWAY

MINOR 

ROADWAY

B D

A C

Figure 2: Typical Access Scenario at the Intersection of Two Public Roadways 

MAJOR 

ROADWAY

MINOR 

ROADWAY

B D

A

C

EF

Figure 3: Desirable Access Scenario at the Intersection of Two Public Roadways 

1.4 Eliminating Left-Turn Movements at Driveways is Beneficial from a Safety Perspective 

Where restricting turning movements to and from a 

driveway is possible, it is most beneficial from a safety 

perspective to prohibit left-turning movements. Research

suggests that approximately 72 percent of crashes at a 

driveway involve a left-turning vehicle [6]. As illustrated 

in Figure 4, approximately 34 percent of these crashes 

are due to an outbound vehicle turning left across 

through traffic. Twenty-eight percent of crashes are 

due to an inbound, left-turning vehicle conflicting with 

opposite direction through traffic, and 10 percent are 

4 FHWA | Access Management in the Vicinity of Intersections 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

due to outbound, left-turning movements 

incorrectly merging into the same direction 

through movement. This suggests that 

reducing or eliminating left turns to or from 

driveways, combined with efforts to reduce 

conflict points (described in Section 1.3), 

enhances safety. When turn movements 

are restricted at driveways, roadway 

engineers, planners, and policy makers 

need to consider the tradeoffs of shifting 

the turning movement to another location 

along the roadway. 

1.5 Median Treatments Can Impact Safety 

One method to manage or limit left turns to and from 

driveways is with the proper use of medians. Proper use 

of medians has been found to improve roadway safety 

significantly relative to undivided roadways. National 

Cooperative Highway Research Program (NCHRP) 

Report 420: Impacts of Access Management Techniques [7] 

identifies two types of medians typically used: 

• Non-traversable medians. 

• Continuous two-way left-turn lanes (TWLTL). 

Non-traversable medians separate opposing 

directions of travel, significantly reducing the potential 

for head-on crashes and physically eliminating or limiting 

where left-turns and crossing movements across the 

median can occur. When a non-traversable median of 

sufficient width is constructed, it can also provide refuge 

28% 34% 10%

Figure 4: Crash Percentages for Turning Motorists to and from the Driveway 

for pedestrians crossing the roadway. Non-traversable 

medians generally result in an overall crash reduction 

of approximately 35 percent as compared to undivided 

roadways. 

TWLTLs provide for left turns in both directions of travel, 

except near signalized intersections where the center turn 

lane transitions to a conventional left-turn lane for one 

direction of travel. TWLTLs generally result in an overall 

crash reduction of approximately 33 percent as compared 

to undivided roadways. However, NCHRP Report 420 

states that “Most studies, and the models derived from 

them, also suggest that safety is improved where physical 

medians replace TWLTLs.” Factors to consider include 

differing roadway types, traffic volumes, travel speed, 

number of through lanes, and the number of left turns 

and crossing maneuvers. 

1.6 Reducing Driveway Density Reduces Crash Rates 

Research over the past decades has 

consistently shown that crash rates 

increase as driveway density increases 

on a roadway (i.e., number of driveways 

per mile). Figure 5 illustrates this trend 

under a variety of roadway conditions and 

environments across the U.S. and in Canada. 

Property access points should be designed, 

approved, and permitted within the context 

of the number of driveways on both sides 

of the street within the vicinity of the 

proposed access points and should not be 

considered in isolation. Possible strategies 

10

8

6

4

2

0

Crashes / Million Vehicle Miles Traveled

1 2

8

7

3

4

5

6 9

1 British Columbia 2-Lane Urban

2 Michigan 2-Lane Urban

3 Michigan 2-Lane Rural

4 British Columbia 4-Lane Urban

5 Florida*

6 Florida*

7 Florida*

8 Oregon Urban*

9 Oregon Rural*

0 10 20 30 40 50 60 70 80 90

Access Points / Mile * Road type not specified

Figure 5: Effect of Access Point Density on Crash Rate 

FHWA | Access Management in the Vicinity of Intersections 5 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

to reduce the number of driveways over time include the 

use of shared access to serve more than one property, 

the planning and development of additional roadways to 

provide connectivity and complementary mixed uses to 

minimize the need for multiple parking areas, and multiple 

driveways. 

1.7 Properly Designed Driveways Influence Safety and Mobility at the Driveway 

Driveway connections to public roads must be 

adequately designed to ensure safe and efficient 

movement of vehicles to and from the roadway, 

balancing safety with mobility interests. There are 

many elements to consider in proper driveway design, 

including upstream and downstream sight distance, the 

angle at which the driveway intersects the major road, 

the appropriate width of the driveway in tandem with 

curb radii so that vehicles can make the desired turn 

movement, the number of lanes (sufficient for the volume 

at the site), and the vertical grade and length of the 

driveway throat. 

In general, driveways should be of sufficient length to 

allow motorists to completely pull off the road without 

interference from on-site parked vehicles, vehicle queues, 

or pedestrian or vehicle circulation once they enter 

the property adjacent to the roadway. The design of 

a driveway at any given location is a function of the 

design vehicle, travel speeds onto and off of the property, 

traffic volume, pedestrian and bicycle volume, and the 

type of traffic control (e.g., a signalized driveway should 

accommodate queues that may conflict with on-site 

turning movements). For motorists leaving a property, the 

vertical alignment of the driveway should be as close to 

level as possible where it intersects with the roadway. The 

driveway should be level for a sufficient distance to allow 

the motorist to easily stop with an unobstructed view 

upstream and downstream prior to entering the major 

roadway. 

The Florida Department of Transportation (FDOT) 

Driveway Manual [8] provides a thorough overview of 

the criteria and application methods that a practitioner 

should consider in the design of a driveway. In addition, 

jurisdiction-specific design guidelines should be 

consulted when designing a driveway. Photo: Ralph Bentley (used with permission) 

6 FHWA | Access Management in the Vicinity of Intersections 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Section 2: Special Considerations for Suburban, Urban 

and Rural Areas 

Urban, suburban, and rural areas each present unique opportunities and challenges with respect 

to design, selection and implementation of access management strategies that provide the highest level of safety in the vicinity of intersections. The following sections (2.1, 2.2 and 2.3) provide an 

overview of some additional special considerations that apply within each of these environments. 

Because suburban areas offer the greatest opportunities to improve safety through access management strategies (due to development trends and traffic volumes), this discussion addresses suburban 

areas first, followed by a discussion of urban and rural environments. 

2.1 Access Management Considerations in 

the Vicinity of Suburban Intersections 

Suburban areas offer the greatest opportunity to 

positively impact safety through access management 

treatments for several reasons. New development 

and redevelopment often occurs on large parcels 

of land, providing planners with more flexibility and 

options for implementing optimal access management 

treatments. This can provide the opportunity for access 

to be considered from a systematic perspective, from 

the outset of a project, where stakeholders have the 

opportunity to plan for the appropriate number of 

driveways and optimum types of access (e.g., right-in/ 

right-out only; or right-in/right-out-left-in). For example, 

access to developments on corner lots may be limited 

to a side street where traffic volumes and speeds are 

typically lower. Where access to a major roadway is 

allowed, agencies with authority over the roadways have 

opportunities to limit turn movements to and from the 

driveway with physical treatments, such as medians along 

the major roadway and/or median islands at locations 

where the driveway connects to the major roadway. 

Further, adjacent land uses, including residential, 

commercial, and industrial require significant access 

management planning and accommodation. Finally, 

while suburban areas are often lower density than urban 

areas, their residential and commercial centers are often 

connected by higher speed arterials (35 to 50 mph and 

occasionally up to 55 mph) than are found in urban areas, 

creating safety risks and opportunities through access 

management planning and implementation. 

This section describes specific characteristics and access 

management challenges and opportunities associated 

with suburban areas and intersections, and provides a 

summary of potential access management treatments 

that can improve safety for motorists, bicyclists, and 

pedestrians. It also features a case study highlighting an 

access management retrofit project in a suburban area. 

2.1.1 Characteristics of Suburban Roads and Intersections 

As the distance from the urban core increases, the density 

of development decreases. Emphasis on residential 

land use grows as one moves further from the urban 

core. Suburban areas tend to be characterized by largescale and residential, commercial, industrial, or retail 

development typically separated by larger distances than 

in the urban core. In developing suburban areas, parcels 

can be combined to accommodate larger developments, 

such as big box retail and strip malls. Land values often 

rely on spacious parking lots and convenient access to 

adjacent roadways. 

Physical characteristics of suburban areas include medium 

to long block lengths that may vary from 400 feet to a 

half mile and signalized intersections on arterials and 

major collectors. Traffic characteristics of suburban areas 

include roadways with speeds that generally range from 

35 to 50 mph (and occasionally up to 55 mph), medium 

to high traffic volumes (30,000 to 50,000 vehicles per day) 

on mainline roadways; and 5,000 to 15,000 vehicles per 

day on side streets and non-residential driveways. Physical 

characteristics include: 

• Moderate to large site setbacks for structures. 

• Non-traversable medians (in some cases) or continuous 

two-way left-turn lanes (TWLTLs) . 

• Left- and right-turn lanes. 

• Six or fewer traffic signals per mile. 

FHWA | Access Management in the Vicinity of Intersections 7 
Table 1 

Reported Crashes on OR 82 at 

Study Driveway (November 1994 to August 1997) 

Total 

Crashes 

Crash Severity 

Fatality Injury PDO Left-turn 

12 0 6 6 12 

PDO = Property Damage Only 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure A: Original Driveway and Roadway Configuration 

Suburban Case Study: La Grande, Oregon 

In June 1996, the Oregon Department of Transportation 

(ODOT) initiated a study of an unsignalized, full-access 

driveway (i.e., left and right turns allowed for inbound and 

outbound vehicles) in a suburban area. The study driveway 

was located on Oregon 82 (OR 82), approximately 600 feet 

south of Walton Road in La Grande, Oregon. La Grande 

has a population of approximately 12,500, and OR 82 is an 

undivided five-lane road. Adjacent land use development 

is a mix of big-box retail, commercial, and some industrial 

uses. The posted speed on this segment of OR 82 is 40 

mph. During a 34-month period 5 between November 1994 

and August 1997, ODOT crash reports show that 12 crashes 

occurred at this unsignalized driveway. Figure A depicts 

this driveway (driveway “A”) and the roadway configuration 

during the study period, prior to implementation of any 

access management treatments. 

All of these crashes included a collision with a vehicle 

moving northbound on OR 82. One of the crashes involved 

a motorist turning left out of driveway “A” onto southbound 

OR 82 and colliding with a motorist traveling northbound 

on OR 82, who was turning right into the driveway. 

After performing a review of the roadway configuration, 

ODOT staff recommended the following access 

management improvements, depicted in Figure B: 

• Restrict left turns to and from the driveway with a 

non-traversable median to eliminate left turns into 

and out of the site. 

• Modify the adjacent signalized intersection to 

accommodate U-turns to allow motorists to access 

southbound OR 82, which has been eliminated at the 

During the study period, the average annual daily traffic 

volumes on OR 82 approached 17,200 in the vicinity of 

driveway “A.” Data also showed that approximately 500 

vehicles per day traveled inbound/outbound on the study 

driveway “A.” The average crash rate was 0.66 crashes per 

million entering vehicles6

. Table 1 summarizes the crashes 

reported during this period. 

driveway with the non-traversable median. 

• Construct a northbound right-turn deceleration lane 

in advance of driveway “A.” This treatment reduces 

the speed differential between motorists slowing 

to access the driveway and following motorists, 

while improving sight distance upstream from the 

driveway. 

The proposed access management treatments were 

approved and funded through the State’s access 

management fund. The State implemented the 

recommended improvements in August 1997. 

RIGHT-TURN LANE

Figure B: OR 82 Roadway Configuration After Implementation of 

Access Management Techniques 

In the ten years following implementation, only two crashes 

have occurred at the unsignalized driveway on OR 82 and 

neither involved another vehicle7

. Given the estimated 

18,900 vehicles per day on OR 82 for the 10-year period 

after the access management treatments were made,8 this 

All equates to a crash rate of approximately 0.06. reported crashes involved left-turning vehicles. Eleven of 

the crashes involved vehicles turning left from the driveway 

onto southbound OR 82. 

5 The 34-month study period represents the time period from when the full access driveway was approved until when ODOT completed mitigation measures. 

6 Crash rate is calculated by: 1) multiplying average daily traffic by the number of years of crash data by 365 days per year, and dividing by 1,000,000 and 2) 

dividing the total number of crashes at the site during the study period by the million entering vehicles calculated in Step 1. 

7 One crash involved a single vehicle and a fixed object, and the other involved a vehicle attempting a left turn across the raised median. 

8 Based on a review of ODOT crash reports for the 10-year period from September 1, 1997, through August 31, 2007. 

8 FHWA | Access Management in the Vicinity of Intersections 
A

X

A X

X

X

X

X X

X X

X X

X X

Traffic signal spacing in suburban areas is a function of adequate progression of traffic on the mainline roadway. 

Roadway and intersection improvement projects often 

are required to provide additional capacity for increasing 

traffic volumes. 

the ability to progress two-way traffic along the mainline 

roadway. Signalized driveways are often not permitted in 

private developments but may be allowed if the spacing 

and timing can meet established standards to ensure 

2.1.2 Potential Access Management Treatments to Improve Safety for Motorists in Suburban Areas 

The following access management 

techniques can help to improve motorist 

safety and mobility at access points 

implemented in the vicinity of suburban 

intersections: 

• Locate driveways upstream of the vehicle 

queue caused when the downstream 

traffic signal is red. Figure 6 illustrates 

this scenario, in which site driveway 

“A” is located beyond the limits of the 

typical queue as shown with the yellow 

(light) vehicles, with current traffic 

volumes. Without changes in capacity, 

existing traffic queues will grow as traffic 

volumes increase. If possible, therefore, 

as development occurs, plan and 

locate driveways for future estimated 

traffic volumes. Figure 7 demonstrates 

potential access issues at driveway “A” 

if future traffic queuing conditions, as 

illustrated with the blue (dark) vehicles, 

are not anticipated. 

• Prohibit median openings to restrict 

driveway movements to and from the

left-turn lane at a major intersection. 

Figure 8 illustrates the risks of allowing 

such a median opening. In this 

example, motorists turning left into the 

site access may confiict with the leftturning or through traffic. 

• In cases where there is a traversable 

median (e.g., TWLTL), aligning 

driveways to have a positive offset to 

minimize confiicts between left-turning 

vehicles is advantageous. Figure 9 

Figure 6: Driveway Location in Relation to 

Traffic Queues on a Major Roadway 

illustrates driveway alignment with a positive offset. With 

a positive offset, motorists can use the two-way, left-turn 

lane to access either driveway with a reduced likelihood 

of a crash. Figure 10 demonstrates a negative offset 

of driveway. In Figure 10 if two motorists are using the 

two-way, left-turn lane at the same time, the drivers’ paths 

Figure 8: Avoid Median Opening Across Left-Turn Lane for Downstream Intersections (Courtesy of FDOT) 

Figure 7: Driveway Location in Relation to 

Future Traffic Queues on a Major Roadway (Blue 

Vehicles with X Indicate Future Traffic Queues) 

would overlap (i.e., a crash may occur) as each driver tries to 

access the driveways. 

• Where it is not possible to align driveways with a positive

offset (as depicted in Figure 10), align driveways directly 

across the street from one another. Figure 11 illustrates this 

technique, which allows drivers to access either driveway 

without utilizing the same median area while decelerating 

prior to turning from the major roadway.

FHWA | Access Management in the Vicinity of Intersections 9 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 9: Locate Driveways on Opposite Sides of Figure 10: Avoid Locating Driveways on Opposite 

Sides of the Roadway that Create an Overlap for 

Left Turns Exiting the Major Roadway 

Figure 11: Align Driveways on Opposite Sides of 

a Roadway to Achieve a Positive Offset the Roadway 

2.1.3 Potential Access Management Treatments to Improve Safety for Bicyclists and Pedestrians in 

Suburban Areas 

The following access management approaches can 

help to improve pedestrian and bicyclist safety as well 

as mobility at access points in the vicinity of urban 

and suburban intersections (both signalized and 

unsignalized): 

• Provide raised medians on the major roadway to prohibit 

vehicles from turning left into driveways. This improves 

pedestrian safety by reducing the number of potential 

pedestrian-vehicle confiicts at a driveway. 

• Construct a channelized island between the inbound and 

outbound movements at right-turn-only driveways to 

provide a pedestrian refuge across the driveway. 

• Minimize the width of the driveway as much as possible in 

order to reduce pedestrian crossing distances (i.e., reduce 

exposure). 

• Place sidewalks and pedestrian driveway crossings so that 

pedestrians are visible to the drivers, and drivers are visible 

to the pedestrians. Do not block pedestrian-driver sightlines with landscaping or signage. 

• Include bike lanes and signage, as appropriate, to alert 

bicyclists that motorists may be entering or exiting a 

driveway and to alert motorists that bicyclists may be 

crossing the driveway. 

2.2 Access Management Considerations in the Vicinity of Urban Intersections 

Implementing access management treatments in urban 

areas can be difficult to achieve because of some of 

the constraints in urban areas and the amount of time 

planning and implementation can consume for local 

jurisdictions. This section describes specific characteristics 

and design challenges associated with access 

2.2.1 Characteristics of Urban Roads and Intersections 

Urban areas (including central business districts) are 

typically characterized by dense, multi-modal, fully 

built-out transportation systems. Adjacent land uses 

are typically high-density office, commercial, and 

management near urban intersections (Section 2.2.1), and 

provides a summary of potential access management 

treatments that can improve the safety for motorists 

(Section 2.2.2), bicyclists, and pedestrians (Section 2.2.3). 

retail developments with minimal setbacks from the 

street. Parking is usually along roadways, in parking 

structures, and in some cases available via surface parking 

lots. Older businesses often rely on on-site parking; 

10 FHWA | Access Management in the Vicinity of Intersections 
therefore, eliminating driveways on these properties can 

significantly impact business operations. 

Physical characteristics of urban environments include 

short block lengths (200 to 350 feet), two-way streets with 

some left-turn lanes, six or more traffic signals per mile, 

and minimal site setbacks. Where there are driveways 

to and from the streets, the driveways have small radii 

and width, and curbs and gutters exist in almost all areas. 

Intersections are controlled with a mix of signalized 

or unsignalized intersections while the driveways are 

generally unsignalized. 

Traffic characteristics include low to medium driveway 

volumes (500 to 5,000 vehicles per day), medium to high 

adjacent street traffic volumes (20,000 to 50,000 vehicles 

per day), and coordinated, fixed signal timing. Pedestrians, 

bicycles, and buses often are present, and speeds 

generally are equal to or below 30 mph. 

One-way couplets are often found within the urban area 

and provide access management benefits. One-way 

streets limit driveways to right-in/right-out only or left-in/ 

left-out only turning maneuvers and reduce the number 

of crossing conflict points and the spacing required 

between adjacent driveways. One-way streets also reduce 

the need for intersection sight distance downstream of a 

driveway as there is no oncoming vehicular traffic. 

One-way streets can also be beneficial for pedestrians 

crossing the street as they only need to look for 

oncoming traffic in one direction. 

Based on a speed of 30 mph, the upstream functional 

area of an urban signalized intersection often exceeds the 

length of a typical urban block. For this reason, engineers 

in urban areas often cannot avoid placing driveways 

within functional areas of intersections. Furthermore, 

on-street parking and other sources of friction within 

an intersection’s functional area, including bus pull-outs 

and areas for truck loading/unloading, can diminish the 

benefits otherwise associated with placing driveways 

outside of the functional area of an intersection. 

2.2.2 Potential Access Management Treatments to Improve Motorist Safety Near 

Urban Intersections 

The following access management approaches can help to 

improve motorist safety and mobility at access points implemented 

in the vicinity of urban area intersections. The techniques apply 

whether or not the urban intersection is signalized: 

• Develop a right-turn lane for inbound vehicles on the through road 

in advance of the site driveway by removing a section of on-street 

parking; this removes the turning vehicle from the fiow of traffic. 

• Avoid locating on-site parking bays near site driveways. This allows 

motorists to drive completely onto the property without having to 

stop for other motorists completing on-site parking maneuvers, as 

illustrated in Figure 12. Parking maneuvers near the site driveway 

can also result in delays for inbound motorists, creating queues 

that extend back into the major roadway. Figure 13 illustrates an 

unobstructed driveway, which allows motorists to exit the roadway 

unimpeded by other motorists maneuvering in the driveway. 

• Replace gated parking entries with alternate ticketing options to 

decrease the driver’s entrance time into the driveway and off the main 

roadway, thus reducing the likelihood of queues on the main roadway. 

• Locate loading and bus bays on the far side of the driveway to 

maximize sight distance for motorists exiting a driveway. 

• Place driveways on lower volume roadways (side streets or alleys) 

wherever possible (Figure 3). 

Figure 12: Parking Maneuvers Close to the Roadway 

Result in Delays for the Inbound Motorist 

Figure 13: Unobstructed and Clearly Defined 

Driveways Allow Easy Access for Inbound Motorists 

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• Sign and stripe for right-turn, outbound movements 

only, wherever possible. It is not always possible to 

enforce this condition without geometric restrictions 

(i.e., raised channelization) to eliminate outbound, leftturning conflicts. 

• Place driveways that serve left-turning, inbound vehicles 

near the center of the block to minimize interaction with 

upstream and downstream intersection queues, thus 

reducing the potential for left-turn related crashes. 

• Place driveways on one-way streets where possible. This 

results in right-in/right-out only or left-in/left-out only 

driveways and therefore fewer confiict points. 

• Position driveways as far upstream from intersections 

as possible to provide motorists leaving a property with 

distance along the roadway to make any necessary 

lane changes for traveling through the downstream 

intersection (e.g., maneuvering into an intersection leftor right-turn lane). 

2.2.3 Potential Access Management Treatments to Improve Safety for Pedestrians and Bicyclists in Urban 

Areas. 

In addition to the access management treatments 

identified in 2.1.3, the following access management 

approaches can help to improve pedestrian and bicyclist 

safety and mobility at access points in the vicinity of 

urban intersections. The techniques apply whether or not 

the urban intersection is signalized: 

• Use colored pavement across driveways in combination 

with crosswalk markings, and audio/visual treatments for 

exiting vehicles with limited sight distance. Such treatments 

include a signal and/or fiashing sign that is activated to alert 

pedestrians a vehicle is about to cross the sidewalk from an 

adjacent parking area. 

• Restrict inbound vehicle speeds by designing the driveway 

access with appropriately designed radii. 

• Smaller driveway radii of 25 to 35 feet are more sensitive to 

pedestrian movements [5] because motorists have to slow 

down to complete the turn. However, on-street parking and 

bike lanes can increase the effective driveway radius, so care 

should be taken to balance vehicle and pedestrian safety. 

2.3 Access Management Considerations in the Vicinity of Rural Intersections 

Rural areas, in general, have fewer access management 

needs in the vicinity of rural intersections than urban 

or suburban areas. Intersections with county roads are 

generally infrequent, and these roads often have fairly 

low traffic volumes. The majority of driveways in the 

vicinity of intersections serve low traffic generators such 

as single family homes and/or farms. Large property 

frontages adjacent to the roadway allow the regulating 

jurisdiction to locate a driveway a significant distance 

from the intersection. However, rural intersections can 

2.3.1 Characteristics of Rural Roads and Intersections 

Rural areas are characterized by low-density commercial 

development, such as gas stations and small convenience 

stores, industrial land and farm land, as well as, in some 

cases, large expanses of private or publicly-owned 

undeveloped property. Large property frontages along 

rural roadways allow jurisdictions to adequately space 

driveways, though topographical and environmental 

constraints (e.g., steep hills, wetlands, or rivers) may 

impact where driveways can be located. 

have intersecting high-speed roadways, which can create 

access management risks. 

This section describes specific characteristics and 

access management challenges and opportunities 

associated with rural areas and intersections, and 

provides a summary of potential access management 

treatments that can improve the safety of motorists, 

bicyclists, and pedestrians. 

Physical characteristics of rural roads include divided 

or undivided two-lane and multilane highways; paved 

and unpaved shoulders; and infrequent full-access, 

unsignalized, and on occasion, signalized intersections. 

Traffic characteristics include speeds of 50 mph and 

higher. Pedestrian and bicycle volumes are typically 

the lowest on rural roads as compared to urban and 

suburban roadways. Rural areas may be subject to 

development in the future. TTI has published research 

on rural intersections that relates driveway frequency 

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to crash frequency. Researchers estimate that a rural 

signalized intersection with no driveways within 250 feet 

“will be associated with 13 percent fewer crashes than an 

intersection with three driveways (say, two driveways on 

one major-approach and one on the other approach).” 

Researchers also estimate that a rural unsignalized 

intersection with no driveways within 250 feet will 

be associated with 20 percent fewer crashes than an 

intersection with three driveways [9]. 

2.3.2 Potential Access Management Treatments to Improve Safety for Motorists in Rural Areas 

The following access management approaches can help 

to improve motorist safety and mobility at access points 

implemented in the vicinity of intersections in rural areas: 

• Early participation by jurisdictional staff and all stakeholders 

in planning processes can help assure that access requests 

do not become problematic for regulating jurisdictions. 

As development occurs in rural areas, a potential concern 

is development of subdivisions or partitions of large 

properties near rural intersections that could create a 

demand for additional access to the major roadway. Early 

communication and coordination with property owners can 

help to establish the location and number of driveways that 

can be permitted to the major roadway as part of the land 

subdivision process. 

• Provide adequate throat depth and on-site circulation for 

vehicles to easily exit a major roadway. This will minimize 

speed differential between through vehicles and vehicles 

slowing to turn into a driveway. 

• Pave the shoulders near driveways to provide additional 

entry and exit width and, hence, higher entry and exit 

speeds to help minimize speed differentials between 

through vehicles and vehicles turning onto or off of the 

roadway within the functional area of an intersection. 

• In situations where there are higher traffic generators in the 

vicinity of rural intersections, frontage roads that parallel 

the major roadway may also be employed as a means to 

provide access to each of the adjacent properties. This 

solution can help to eliminate several access points to the 

major roadway as access to each development is achieved 

via the frontage/backage road rather than to the major 

roadway. In instances where the intersecting roadway 

has high traffic volumes, the jurisdiction may elect to 

implement some type of grade-separated facility rather 

than allow the installation of a traffic signal on a high-speed 

corridor. 

2.3.3 Potential Treatments to Improve Safety for Pedestrians, and Bicyclists in Rural Areas 

In rural areas, where there is no sidewalk, pedestrians 

and bicyclists benefit from roadway shoulders that are 

at least 4 feet wide or wider, paved and well maintained. 

As access and intersection modifications are considered 

in these environments, to the extent possible, shoulder 

widths should be maintained in order to provide facilities 

for non-auto travelers. Figure 14 depicts an example of a 

paved shoulder for bicycles or pedestrians on a rural road. 

Photo: Kittelson & Associates, Inc. (used with permission) 

Figure 14: Paved shoulder for bicycles or pedestrians 

FHWA | Access Management in the Vicinity of Intersections 13 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Section 3: References 

The following documents were referenced in the development of this technical summary. 

1. Roundabouts: An Informational Guide, Report FHWA-RD-00-067. FHWA, U.S. Department of Transportation, June 

2000. This comprehensive guide is anticipated to be published in 2010. It will include the most recent research 

and findings for the design and implementation of roundabouts in the U.S. 

2. A Policy on Geometric Design of Highways and Streets, AASHTO 2004. Commonly referred to as the “Green Book,” this 

manual provides the transportation professional with a wide array of guidelines for the design and operation of 

roadways and streets. 

3. Access Management Manual, Transportation Research Board. Washington, D.C. 2003. A comprehensive overview 

on access management, the Access Management Manual provides information on how to develop a State or local 

access management program. The manual also includes sections on corridor management, land development, 

access location and spacing criteria, medians, public involvement, right-of-way and legal concerns, driveway 

applications and permitting processes, and case studies. 

4. G. Schultz, C. Allen, and D. Eggett. Crashes in the Vicinity of Major Crossroads, Brigham Young University, 

Department of Civil and Environmental Engineering for the Utah Department of Transportation, December 2008. 

The study focuses on the evaluation of crashes in the vicinity of signalized -intersections in suburban areas. 

5. J. Bonneson, K. Zimmerman, and K. Fitzpatrick, Roadway Safety Design Synthesis, Texas Transportation Institute, 

November 2005. This document describes the effect of key design components on street and highway safety. 

6. Analysis of Crossing Path Crashes, U.S. Department of Transportation. July 2001. This 76-page report examines 

crossing path crashes within the physical area of an intersection, including contributing factors to the crashes 

and a section on pedestrian and bicyclists’ crashes at intersections. 

7. Report 420, Impacts of Access Management Techniques, Transportation Research Board. Washington, D.C. 1999. This 

170-page report presents access management techniques and provides methods for estimating the safety and 

operational effects of different techniques. The report was a precursor to the 2003 Access Management Manual. 

8. Florida Driveway Information Guide, Florida Department of Transportation, September 2008 (http://www.dot.state. 

fl.us/planning/systems/sm/accman/pdfs/driveway2008.pdf). This guide provides a comprehensive overview 

on issues related to driveways including information on appropriate connection radii and flare, driveway width, 

grade and length, sight distance considerations, optimum location for a driveway, and pedestrian considerations. 

9. J. Bonneson, K. Zimmerman, and K. Fitzpatrick, Roadway Safety Design Synthesis, Texas Department of 

Transportation, 2005. The synthesis includes safety information related to freeways, interchange ramps, rural 

highways and intersections and urban streets and intersections. 

14 FHWA | Access Management in the Vicinity of Intersections 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The following web sites offer two of the most comprehensive portals available for online access management 

information: 

• FHWA Access Management Web site: http://www.ops.fhwa.dot.gov/access_mgmt/resources.htm 

The web site provides links to FHWA resources and publications published on access management topics, including 

videos/CDs; brochures, including the Benefts of Access Management (2003); the publication Safe Access is Good for 

Business (2006), with accompanying CD; contact information for the National Highway Institute 3-day classroom 

course “Access Management, Location and Design”; and a link to the Access Management Manual at the TRB Bookstore. 

The FHWA materials and classroom course will be especially beneficial for those involved in public outreach and 

coordination and those desiring to learn more about the technical and legal aspects of an access management 

program. 

• TRB Access Management Committee: http://www.accessmanagement.info/ 

The site includes information on all of the access management related publications that have been developed within 

the United States and many other countries in the past two decades. The site provides links to published research 

(including NCHRP reports); guides and handbooks for the practitioner; outreach materials; papers, PowerPoint and 

video presentations from past access management conferences; information on upcoming conferences and future 

research needs; and policies and programs from international, state, and local agencies. 

FHWA | Access Management in the Vicinity of Intersections 15 
For More Information 

Jeffrey Shaw

Intersection Program Manager, 

FHWA Office of Safety 

202.738.7793

jeffrey.shaw@dot.gov

Visit FHWA’s intersection safety web site to download this 

and other technical outreach products highlighting proven 

intersection safety treatments from across the country: 

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

FHWA-SA-10-002 Updated July 2020