Whole Roads or Section of Roads including lane maintained by LTA.

Collector roads are built primarily to feed traffic from local onto arterial roads. It also provides access to adjacent land uses. Local access roads provide access to various types of land uses. These roads are generally smaller, in terms of width, than collector roads. All public roads maintained by LTA are paved.

Road Length in lane-km data includes all public roads maintained by the Land Transport Authority. It does not include certain roads such as those maintained by the National Parks Board (Nparks), Housing and Development Board (HDB) and Urban Redevelopment Authority (URA), JTC Corporation (JTC) - including roads in Jurong Island , National Environment Agency (NEA) , Ministry of Home Affairs (ISD), Ministry of Home Affairs (POLICE), Singapore General Hospital (SGH) , Public Utilities Board (PUB), Singapore Land Authority (SLA) , AGRI-Food and Veterinary Authority of Singapore (AVA) as well as roads within Sentosa Island (SDC), airports (CAAS), seaports (PSA), universities (NTU, NUS), Community Improvement Project Committee (CIPC) , Private, Ministry of Home Affairs (prisons), Immigration & Checkpoints Authority (ICA) and military (MINDEF) areas.

The road length is shorter than the as build roads due to re-alignment of Changi Coast Road (Major Road) and Changi Ferry Road (Collector Road).