Key dimensions of nonmotorized design users. Radial alignment of entries. Recommended inscribed circle diameter ranges. Approach widening by adding full lane.

This guidance reviews the planning and design of roundabouts in Kentucky and is supplemented by guidance from National Cooperative Highway Research Program (NCHRP) Report 1043 …

Generally, the inscribed circle diameter of a multilane roundabout ranges from 150 feet to 250 feet. For two-lane roundabouts, a common starting point is 160 feet to 180 feet. Roundabouts …

Roundabouts are separated into three basic categories according to the size and number of lanes used at the roundabout: mini-roundabouts, single-lane roundabouts, and multilane roundabouts.

The size of a roundabout, measured by its inscribed circle diameter (see Figure 2), is determined by a number of design objectives, including design speed, path alignment, and design vehicles …

There are five basic roundabout types: mini, compact, single-lane, multilane, and teardrop described in the following sections. Mini-roundabouts are small single-lane roundabouts …

s many of the geometric dimensions of roundabouts. For the purposes of design, vehicles are classified as (i) passenger car a d single-unit trucks, (ii) buses and (iii) trucks. Table 3.2 …

The mission of the Center for Transportation Research and Education (CTRE) at Iowa State Uni-versity is to develop and implement innovative methods, materials, and technologies for …

The size of vehicle to accommodate at a roundabout should be based on the type of roadway, volume and type of vehicles expected, and the intersection location. There are two types of …

To more clearly identify the defining characteristics of a roundabout, consistent definitions for each of the key features, dimensions, and terms are used through-out this guide.