Passing lanes may be installed on divided or undivided roads. Signs, markings, and geometric considerations in this section apply to divided and undivided roads unless otherwise stated.
Passing lanes should be provided where the traffic volume, crash record, and / or composition of traffic is such that it is desirable to provide an additional lane for overtaking slower moving vehicles. Provision of a passing lane (or passing lanes) may be accommodated by creating a two-lane two-way, two plus one, three lane, or four lane layout. Specific markings and signs are used to encourage and control traffic overtaking within the limits of these types of lane configurations.
For guidance on the design of passing lanes, refer to the following documents:
The publications listed above contain guidelines for the provision of passing lanes based on Annual Average Daily Traffic (AADT) and percentage of slow vehicles.
