sentences:  Additional factors making the Portland Streetcar line less expensive to build per mile than light rail are that use of city streets largely eliminated the need to acquire private property for portions of the right-of-way, as has been necessary for the region's light rail lines, and that the vehicles' smaller size and therefore lighter weight has enabled the use of a "shallower track slab".The latter means that construction of the trackway necessitated excavating to a depth of only instead of the conventional (for light rail) depth of around , significantly reducing the extent to which previously existing underground utilities had to be relocated to accommodate the trackway.Each Portland streetcar is long, whereas light rail cars are typically long (Portland's Lightrail are between .