Objective

Today’s transportation professionals, with limited 

resources available to them, are challenged to 

meet the mobility needs of an increasing population. At many highway junctions, congestion continues to worsen, and drivers, pedestrians, and 

bicyclists experience increasing delays and heightened exposure to risk. Today’s traffic volumes

and travel demands

often lead to safety 

problems that are 

too complex for 

conventional intersection designs to 

properly handle. 

Consequently, more 

engineers are considering various innovative treatments as 

they seek solutions 

to these complex 

problems. 

The corresponding 

report, Alternative

Intersections/Interchanges: Informational 

Report (AIIR) (FHWAHRT-09-060), covers 

four intersection designs and two interchange designs that 

offer substantial advantages over conventional at-grade intersections and gradeseparated diamond

interchanges. The AIIR provides information on

each alternative treatment covering salient geometric design features, operational and safety 

issues, access management, costs, construction 

sequencing, environmental benefits, and applicability. This TechBrief summarizes information on 

one of these alternative intersection designs—the 

quadrant roadway (QR) intersection (see figure 1).

Research, Development, and Technology Turner-Fairbank Highway Research Center 300 Georgetown Pike, McLean, VA 22101-2296

www.tfhrc.gov

TECHBRIEF

FHWA Publication No.: FHWA-HRT-09-058

FHWA Contact: Joe Bared, HRDS-05, (202) 493-3314, joe.bared@dot.gov

This document is a technical summary of the Federal Highway Administration 

report, Alternative Intersections/Interchanges: Information Report (AIIR)

(FHWA-HRT-09-060).

Quadrant Roadway Intersection

Figure 1. QR intersection geometry.

200’ 150’

500’

200’ 150’ 200’ 150’ 200’ 200’ 150’ 150’

R 250’

R 100’

4’

28’

28’
2

Introduction

A QR intersection is a promising design for an 

intersection of two busy suburban or urban 

roadways. The intersection works by rerouting 

all four left-turn movements at a four-legged 

intersection onto a road that connects the two 

intersecting roads. Figure 1 shows the geometry 

of a QR intersection where the connection road 

is placed in the southwest quadrant. The location 

of the connector road depends on traffic flow and 

availability of right-of-way. Figure 2 shows how 

all four of the left-turning movements are rerouted 

over the connector road. This design prohibits 

all left turns at the main intersection and therefore allows a simple two-phase signal to process 

the remaining through and right-turn movements. 

Both junctions of the connector road are typically 

signalized.

The QR intersection concept was first published 

in 2000.(1,2) Since then, its design has been 

explored by others, including the Federal Highway 

Administration (FHWA). However, as of July 2009, 

no known highway agency has implemented a 

QR intersection in the United States.

Geometric Design

The primary design considerations of the QR intersection are as follows:

•	 The location of the connector road should be 

primarily determined by the left-turn volume

at the intersection. As seen in figure 2, drivers 

seeking to make a left turn who approach 

from the cross street opposite the quadrant 

are required to travel through the main 

intersection, make three right turns, then 

travel back through the main intersection. 

These drivers travel the longest distance to 

make the left turn. Conversely, drivers turning 

left who approach from the cross street on 

the same side of the quadrant are not required 

to travel through the main intersection at 

all, and their travel distance is about the same 

as at a conventional intersection. Therefore, 

if right-of-way is available, the connector 

road-way should be located to allow the 

highest volume of left-turn traffic and the 

most direct path.

•	 U-turns are not permitted at the main 

intersection and are rerouted similar to left 

turns.

•	 Distance of the secondary intersections 

from the main intersection should provide 

adequate storage for vehicles, signing, and 

sight distance. Reid recommended spacing 

the secondary intersections ±500 ft from the 

main intersection.(1)

•	 If permitted, driveways from the connecting 

road to the parcel inside the connecting 

road may be placed in the curve of the 

connecting road or near one of the secondary 

intersections. If driveways are not permitted, 

Figure 2. Movements in a QR intersection.

A) Left-turn pattern 

from the arterial

B) Left-turn pattern 

from the cross 

street

Arterial Arterial

Quadrant 

roadway

Quadrant 

roadway

Cross Street

Cross Street
3

then the parcel inside the connecting roadway can be accessed via driveways off one 

or both of the intersecting streets. 

•	 At a QR intersection, some pedestrians 

will need to cross an extra street; however, 

others who follow the curved connection 

roadway or the main intersection crosswalks 

will have shorter walking distances. Also, 

the shorter cycle lengths at QR intersections 

benefit pedestrians. 

•	 A QR with more than one connection road can 

be implemented if right-of-way is available 

and if left-turn volumes justify it. Geometric 

principles remain largely the same for QRs 

with one or more connection roadways.

Traffic Signal Control

A QR intersection needs three sets of signalcontrolled junctions—the main intersection with 

two signal phases and two secondary intersections at the ends of the connecting road with three 

signal phases each. These junctions are shown 

in figure 3.

Operational Performance

The traffic simulation software VISSIM was used 

to compare the operational performance of QR 

intersections to conventional intersections. Four 

intersection geometric design cases of QR and 

conventional intersections were simulated under 

four traffic volumes scenarios. The findings for 

throughput showed a 5- to 15-percent increase 

for travel time and a 5- to 20-percent reduction 

compared to conventional intersections.

Safety Performance

Since a complete QR intersection has not yet been 

built, safety data are not available. Nonetheless, 

Figure 3. Typical QR intersection signal locations.

Typical Signal Locations
4

Researchers—This study was performed by Principal Investigators Warren Hughes and Ram Jagannathan. For 

more information about this research, contact Joe Bared, FHWA Project Manager, HRDS-05 at (202) 493-3314, 

joe.bared@dot.gov. 

Distribution—This TechBrief is being distributed according to a standard distribution. Direct distribution is 

being made to the Divisions and Resource Center.

Availability—This TechBrief may be obtained from the FHWA Product Distribution Center by e-mail to 

report.center@dot.gov, fax to (814) 239-2156, phone to (814) 239-1160, or online at http://www.tfhrc.gov/safety.

Key Words—Quadrant roadway intersection, QRI, QR, and Alternative intersection.

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. The U.S. Government does not endorse products or manufacturers. Trademarks or 

manufacturers’ names appear in this report only because they are considered essential to the objective of the 

document.

Quality Assurance Statement—The Federal Highway Administration (FHWA) provides high-quality information to serve the Government, industry, and 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.

October 2009 FHWA-HRT-09-058

HRDS-05/10-09(3M)E

the QR has 28 conflict points more widely spread 

out than compared to 32 at a conventional intersection. This reduction in conflict points suggests 

the QR may be safer, although a definitive relationship between conflicts and safety has not yet been 

established.

Applicability

QR intersections will typically be spot treatments. 

They are most applicable where the following 

exists:

•	 A roadway in the road network can be used 

as a connection roadway.

•	 There are heavy left turns and through volumes on the major and minor roads.

•	 The minor road total volume to total intersection volume ratio is typically less than or 

equal to 0.35.

Summary

The QR intersection increases operational 

efficiency through a congested intersection by 

moving the left turns away from the main 

intersection and allowing a two-phase signal at 

the main intersection. While additional right-ofway would be needed in the connection road 

quadrant, and extra cost would be necessary to 

build the connecting roadway, the QR intersection could be used to reduce congestion at a busy 

intersection in a developing area. It could also 

serve as a temporary congestion reliever until a 

grade-separated solution can be built. In addition, 

the QR intersection accommodates pedestrians 

well. More details can be found in the full AIIR

available from the FHWA.

References

1. Reid, J.D. (2000). “Using Quadrant Roadways 

to Improve Arterial Intersection Operations,” 

ITE Journal, 70(6), 34–45.

2. Reid, J.D. and Hummer, J.E. (2001). “Travel 

Time Comparisons Between Seven Unconventional Arterial Intersection Designs,” Transportation 

Research Record 1751, 56–66.