A cable car is superficially similar to a funicular, but differs from such a system in that its cars are not permanently attached to the cable and can stop independently, whereas a funicular has cars that are permanently attached to the propulsion cable, which is itself stopped and started. A cable car cannot climb as steep a grade as a funicular, but many more cars can be operated with a single cable, making it more flexible, and allowing a higher capacity. During the rush hour on San Francisco's Market Street Railway in 1883, a car would leave the terminal every 15 seconds.