Traffic calming
The decision to install a roundabout for traffic calming purposes should be supported by a demonstrated need for traffic calming along the intersecting roadways. Most of the roundabouts in this category will be located on local roads. Examples of conditions that might suggest a need for traffic calming include:
- Documented observations of speeding, high traffic volumes, or careless driving activities;
- Inadequate space for roadside activities, or a need to provide slower, safer conditions for non-automobile users; or
- New construction (road opening, traffic signal, new road, etc.) which would potentially increase the volumes of “cut-through” traffic.
Capacity should be an issue when roundabouts are installed for traffic calming purposes only because traffic volumes on local streets will usually be well below the level that would create congestion. If this is not the case, another primary selection category would probably be more suitable. The urban mini-roundabout or urban compact roundabout are most appropriate for traffic calming purposes. Exhibit 3-4 provides an example of roundabouts installed primarily for traffic calming.
