Program Contact

Jeffrey Shaw
jeffrey.shaw@dot.gov

Intersection Safety

About Intersection Safety

Safe System Intersections

Intersection Control Evaluation

Corridor Access Management

Stop–Controlled Intersections

Signalized Intersections

Roundabouts

Reduced Left–Turn Conflict
Intersections

Crossover Intersections

Other Intersection Designs

In The News

Resources

Contacts

Crossover Intersections

Some intersection designs direct some or all traffic to cross over to the left–hand side of the roadway to facilitate unopposed left–turn movements. These designs can improve safety and reduce congestion at the intersection.

The two most common crossover–based designs are the diverging diamond interchange (DDI) and the displaced left–turn (DLT) Intersection.

Outreach and Education Resources

Alternative Intersection Video Playlist – includes DDI and
DLT intersections

Diverging Diamond Interchanges

Diverging Diamond Interchange Brochure
Diverging Diamond Interchange Case Studies

Displaced Left–Turn Intersections

Displaced Left–Turn Intersection Brochure
Displaced Left–Turn Case Studies

Technical Materials and Research

Diverging Diamond Interchanges

Diverging Diamond Interchange Informational Guide, Second Edition
Performance of Alternative Diamond Interchange Forms
- Volume I: Research Report
- Volume II: Guidelines for Selecting Alternative Diamond Interchanges
Exploring Corridor Operations in the Vicinity of a Diverging Diamond Interchange (DDI): Final Report
Comprehensive Safety Assessment Methodology for Innovative Geometric Designs

Displaced Left–Turn Intersections

Connections to Other Transportation Safety Topics

The Federal Highway Administration's (FHWA) EDC–2 initiative for Intersection and Interchange Geometrics developed educational materials about DDIs, DLTs, and other intersection designs
Roundabout, restricted crossing U–turn (RCUT) , and median U–turn (MUT) intersection designs also offer improved safety due to fewer conflict points
Intersection Control Evaluation (ICE) policies and tools can help agencies choose an optimal intersection design
Low–cost strategies and countermeasures can improve safety. Learn more at Stop–Controlled Intersection Safety and Signalized Intersection Safety

Source:MoDOT,FLKR,CC BY 2.0

Top Resources

Alternative Intersection Video Playlist – includes DDI and DLT intersections
Diverging Diamond Interchange Brochure
Diverging Diamond Interchange Informational Guide, Second Edition
Displaced Left–Turn Intersection Brochure
Displaced Left–Turn Intersection Informational Guide

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Image sources: About Intersection Safety: MoDOT, FLKR, licensed under CC BY 2.0.; Safe System Intersections: deberarr, iStock/Getty Images Plus; Intersection Control Evaluation: CreativeNature_nl, and smolaw11, iStock/Getty Images Plus; Stop–Controlled Intersections: James Andrews, iStock/Getty Images; Corridor Access Management: FHWA; Roundabouts: FHWA; Crossover Intersections: FHWA; Reduced Left–Turn Conflict Intersections: FHWA; Signalized Intersections: FHWA; Other Intersection Designs: NCDOT

Page last modified on August 23, 2021