Street-running trains

Street-running trains are trains that run through a built-up area in a mixed-traffic area (which can include pedestrian streets where economic activity occurs). These differ from trams or light rail systems in that full-sized trains run on these streets, making such trains considerably rare.

In much of the developed world, street-running trains are most often found in smaller cities that see lower traffic. However, in the developing world, it is entirely possible to see train lines run through pedestrian streets full of economic activity, making them interesting travel destinations (particularly if you're not used to seeing organised chaos). Perhaps the most famous is the Hanoi Train Street in Vietnam, but similar streets exist elsewhere that give a similar experience.