Looking at my current city of residence-
Calgary elected a light rail transit system (Siemens) over 20 years ago. To date, essentially there is one N-S line and an E to N line connected to the east side of that one.
Although daily ridership is approaching 300,000, most of the city is served by buses (service slow and frustrating, with transfers, from many districts). There are plans for light rail expansion but costs are killing.
Car transport is necessary in a city that has spread over a very large area, and includes suburban developments outside of city limits. The metro area is roughly 1,970 sq. mi. and the metro population 1,200,000.

The roadway and the car will be predominant for the forseeable future. Taxpayers will not authorize the money necessary to move light-rail to a dominant position. The trolley system was dismantled some 50 years ago, and overhead lines aesthetically are no longer acceptable.