Service roads, or frontage roads, run parallel to a main road and allow local traffic to gain access to property. Where major roads are bordered by commercial or residential development, service roads are a safe way to allow vehicles to access these properties with little disruption to other traffic.

Also crashes can occur where a commercial development is fronted by parking spaces with uncontrolled access to the carriageway, and service roads can be used to bring traffic to a single and safe T-junction at the main road.