Median U-Turn (MUT) retrofit

#Applicability and thresholds

Requires a wide enough median, or the ability to widen one, to accommodate the U-turn movement, sized to the corridor's design vehicle. Most commonly applied on divided arterials and highways with four or more lanes, where a conventional left turn from the minor approach would otherwise cross multiple lanes of opposing traffic at once.²

#Evidence and effectiveness

State DOT data (Indiana) shows a MUT-style retrofit improving traffic capacity by 20 to 50 percent at the retrofitted intersection, through more efficient signal phasing, timing, and progression with adjacent intersections, and reduces stops by a third or more.¹³

#Getting it built

Cannot be piloted informally. Retrofitting a standard intersection to this geometry costs from a few hundred thousand dollars to more than a million, and requires real median construction and, often, signal relocation. This strategy effectively starts at Permanent on the construction spectrum. See Construction Methodology & The Build Spectrum.

An Intersection Control Evaluation is standard practice, comparing this geometry against a conventional signal or other alternative intersection designs using safety and operational data. See Decision & Evaluation Processes.

#Who can move this

Typically a state DOT capital project, given the scale of median reconstruction involved, though a state highway running through a small city may still be responsive to local advocacy given the safety case. See Legal & Planning Mechanisms and Funding & Financing Mechanisms.