Lane narrowing reduces the width of the travel portion of a lane and gives drivers a feeling of constraint that can influence them to reduce their speed.

Treatment Options

Lane narrowing reduces the width of the travel portion of a lane. Narrowed lanes provide a feeling of constraint that can influence drivers to reduce their speed. Lanes can either be physically or visually narrowed. Physical narrowing is achieved through construction efforts such as widening or adding center islands, curb build-outs, or chicanes. Visual narrowing is often a maintenance effort which re-orients the longitudinal pavement markings resulting in a reduced lane width. This section discusses the following narrowing treatments:

Center island (Neal Hawkins/Institute for Transportation)

Image: Street view of a vertical centerline constructed with reflective posts and a 25 mph speed limit sign as entering

Vertical centerline (Shauna Hallmark/Institute for Transportation)

Shoulder widening (Neal Hawkins/Institute for Transportation)

Four- to three-lane conversion (Neal Hawkins/Institute for Transportation)

Landscaping (Neal Hawkins/Institute for Transportation)

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