Pedestrian Safety Guide and Countermeasure Selection System


Illustration of a modified T-intersection.

Photo by Peter Lagerwey A mini traffic circle used at a T-Intersection forces motorists to slow down.
Photo by Peter Lagerwey




Modified T-Intersections

A modified T-intersection is designed so that vehicles traveling straight along the top of the intersection are deflected slightly and forced to slow down using curb extensions, medians, or mini traffic circles (see diagram). Such intersection treatments may also be accompanied by signage and/or pavement markings to warn motorists of the treatment and to slow down. Modified T-intersections can also help to discourage cut-through traffic on local neighborhood streets by restricting certain traffic movements. Modified T-intersections should always provide bicycle and pedestrian access.


Where speeding is of concern at T-intersections (3-leg intersections) on low-volume residential or collector streets, this treatment modifies the geometry of the intersection to reduce vehicle speeds.


• This treatment should be considered when vehicle volumes are low to moderate, and slower traffic speeds are desired.
• Consider installing a mini traffic circle before other treatments are considered. A mini-traffic circle may accomplish the same objective and be less costly and confusing.
• Intersection geometry, regulatory and warning signage, and/or pavement markings should clearly direct motorists at the intersection to reduce confusion regarding priority of movement.
• When designing the curb radii of curb extensions, consideration should be given to emergency vehicle access.3,4

Estimated Cost

$20,000 to $60,000, depending on the design and whether drainage and utilities need to be relocated. See the sections on curb extensions, medians, and mini circles for the specific cost of these measures.

Case Studies