Researching one of my hometowns, I found a photo of a streetcar line built to the same standards as the Norwell, Massachusetts line, maybe 25 miles away. Over a hundred years ago

Single track, literally at the side of one-lane dirt roads, up-down-and around. Single wood poles carrying the trolley wire on arms toward the dirt road, plus a fabric insulated feeder and a telephone line. Yes, voltage was a little "thin" too far from the substation. High-end substations used commercial power and rotary converters. Low-end substations were steam powered, fed by a neighbor. (Remember a newspaper cartoon that included a two-axle streetcar.)

"train control" was by public schedule and short passing sidings or spurs.
(I remember Pacific Great Eastern using mill spurs for scheduled passing.)

Emergencies: hand-crank telephones, ground rods, and hot sticks

That same train control system worked 100% on our single-track Seattle Waterfront Streetcar. We had a two-car pattern and a three-car pattern. And keep your headlight on.