A Curb, when used as a noun, is a restraining ribbon of various materials, demarcation between the road for traffic and a pedestrian walkway, an enclosing frame, border, or edging, a raised edge meant to strengthen or confine, and an edging of concrete built along a street to form part of a gutter.
Pompeii, Italy
Curbs with raised sidewalks beside a 2000-year-old paved road.
The first use of Curbs can be traced back to the Romans who used them to control street traffic keeping it separate from pedestrian walkways, and to define the road. Curbs also helped send the water runoff from the road, which were slopped towards it, down the gutter to the sewer. Curbs worked well to raise the walkway up from the street level; this would help move traffic along the road faster than the sidewalks where commerce would be slowing things down. The Romans would not allow the use of carts in urban areas, exceptions were made for Married women, and Government officials on business could ride. “All Roads lead to Rome” no one really knows how old this metaphor is as it was already in use during the 11th century, and certainly back then was very true as the Romans were the most prolific road builders among Ancient Civilizations. However, widespread construction and use began in the 18th century- specifically in the streets of London.
The building of a road in New York during the 1800’s.
In the United States, during the Industrial Revolution, 1780-1850, many people seeking a better life, and hearing of factory jobs for all who wanted one poured into the larger cities such as New York, and Philadelphia. The population grew so rapidly the new comers could not find housing. In answer, to meet this need multiple apartment structures, or rather at that time, tenements were built. They were filled to capacity and beyond as people flooded into areas to live and work hoping for a better future. The structures were built along a grid pattern of streets from the center of the city. Only at this time, the streets ended up being the conveyor/storage of all types of wastes Human, industrial, and plain garbage. The only time it conveyed the miasma away is when it rained. But when it rained heavy, it swept all this microbe rich garbage laden water back into homes. One quick fix to keep the filth from reentering the homes was the building of curbs- sometimes a foot high- which would then channel the waste water away from the homes. Because of curbs, everywhere but the street was relativity clean.
Modern curbs separate the road from sidewalks, lawns, and storm channels. Curbs are an added cost to a road so they are not often found in rural areas; mostly they are used in urban and suburban areas.
On roads traveled at low speed curbs are used safely and effectively to keep vehicle traffic off sidewalks, lawns, and mediums. However, at high speed they are dangerous because when a vehicle traveling at a high rate of speed hits a curb it may actually be directed toward the sidewalk rather than away, or it can be tripped into a rollover or vaulted into the air- perhaps over a traffic barrier on its way to do a lot of destruction and perhaps cause loss of life.