In the past, big tunnel building projects had roads with surfaces made of concrete. The reasons for using concrete surfaces were mainly the long durability of these types of roads, the low maintenance costs, good roughness and, to no small degree, the fact that such surfaces absorb less light and thus help save money on lighting while increasing driver safety. Also, ruts, which decrease driver safety, do not develop on concrete roads. In the 1980s, asphalt-concrete surfaces were used in tunnels with increasing frequency, mainly where the roads immediately connected to the tunnels had asphalt surfaces.