Up to the early 19th century even the major cities were quite compact and not many people had to travel more than a walking distance. The places they wanted to go to were few, limited to their workplace (if indeed they worked outside the house), the market, and church. In any case people were powerful walkers and even the well-to-do, with more extended social networks, were quite willing to walk ten km or so to lunch or take tea with a friend. Mobility was not an issue for most people.
The accelerating industrialization of the 19th century brought prosperity (for some), and many more jobs outside the home although often at starvation wages. Tireless machinery forced punctuality on the workers, often children, who tended them. Cities expanded, shops multiplied, as did workplaces. People had to become more mobile. However, it still took some time before conditions for public transport fell into place, an important one being the growing spatial separation of commercial, industrial, residential and residential functions within the expanding city (like spots on an expanding balloon). Eventually, demand for regular transport services along certain fixed routes grew to the point where it could be satisfied profitably. Omnibus services were put into place in London and Paris around the 1830’s. They consisted of enclosed horse-drawn vehicles with a capacity of up to twenty passengers.
A decade or so later a second level was added and capacity grew to over thirty, sometimes requiring up to three or four horses.The investment in horses was high (sadly more than in the drivers who could he hired and fired at will) since demand for public transport being cyclic, most of them worked only a few hours a day but they still had to eat and be tended and housed. Rails came into general use from about 1860. The reduced rolling resistance made it possible to transport more people or reduce the number of horses. Generally it allowed the number of horses to be reduced by one-third.
Large quantities of electric power distributed from fixed installations become available in urban areas during the 1880’s, at first mainly for lighting. Initially an energized rail provided energy but for safety reasons it was moved to an overhead line. It took some time to find a way of keeping the tram in more or less permanent contact with the wire (the connection was often lost and journeys were often enlivened by the tram grinding to a halt, forcing the conductor out to reattach it using a fishing rod-like device).
By the 1890’s trams were a symbol of progress in any self-respecting city (as they are again today). They generated great affection during their sixty years of service as was witnessed by the gigantic crowds at their final runs during the 1950’s.The problem with trams was that they tended to both hold up traffic and be held up by it. Also they were stuck on fixed routes with considerable supplementary investment required to expand the network.For this reason the trolleybus came into use during the first decade of the 20th century. It provided more operating flexibility but still required those limiting and expensive overhead wires. It was however silent and non-polluting.
The bus was seen as a great innovation, nimble and flexible, and independent of fixed infrastructure. Once the internal combustion engine was reliable enough they proliferated, since it didn’t take much capital to put a few buses on the high density routes. By 1910 they were commonplace. Competition for passengers was fierce until regulation was put into place to limit the number of operators. Buses grew in power and capacity. Today, those in use on high density urban routes in the UK and Ireland are, capable of transporting a hundred passengers. However, buses as a mass transport mode are not ideal. They are polluting, not all that comfortable, and with high operating costs. They also tend to get caught in the congestion they are supposed to alleviate. Reserved bus lanes can help but they still become less competitive with the private car as urban incomes rise.The future lies with tramways and light rapid transit (LRT) for primary routes, with buses playing a feeder role over short distances.