Controlled-access highway

A controlled-access highway is a type of highway which has been designed for high-speed vehicular traffic, with all traffic flow and ingress/egress regulated. Common English terms are freeway (in the US), motorway (in the UK & Ireland) and expressway (in Canada and many Asian countries). Terms in other languages sometimes seen in English include Spanish: autopista or autovía (depending on whether it has toll or not), French: autoroute, German: Autobahn, or Italian: autostrada. Other similar terms include Interstate and parkway. They may also be called limited-access highways, although this term can also refer to a class of highway with somewhat less isolation from other traffic. Conversely, some of the United States use "controlled access" to describe a non-limited-access road, entrances to which are controlled by the state.

A controlled-access highway provides an unhindered flow of traffic, with no traffic signals, intersections or property access. They are free of any at-grade crossings with other roads, railways, or pedestrian paths, which are instead carried by overpasses and underpasses across the highway. Entrances and exits to the highway are provided at interchanges by slip roads (ramps), which allow for speed changes between the highway and arterial roads and collector roads. On the controlled-access highway, opposing directions of travel are generally separated by a median strip or central reservation containing a traffic barrier or grass. Elimination of the sources of potential conflicts with other directions of travelers dramatically improves safety, and capacity.

World

World is a common name for the whole of human civilization, specifically human experience, history, or the human condition in general, worldwide, i.e. anywhere on Earth or pertaining to anywhere on Earth.

In a philosophical context it may refer to:

In a theological context, world usually refers to the material or the profane sphere, as opposed to the celestial, spiritual, transcendent or sacred. The "end of the world" refers to scenarios of the final end of human history, often in religious contexts.

World history is commonly understood as spanning the major geopolitical developments of about five millennia, from the first civilizations to the present.

World population is the sum of all human populations at any time; similarly, world economy is the sum of the economies of all societies (all countries), especially in the context of globalization. Terms like world championship, gross world product, world flags etc. also imply the sum or combination of all current-day sovereign states.

Traffic congestion

Traffic congestion is a condition on road networks that occurs as use increases, and is characterized by slower speeds, longer trip times, and increased vehicular queueing. The most common example is the physical use of roads by vehicles. When traffic demand is great enough that the interaction between vehicles slows the speed of the traffic stream, this results in some congestion.

As demand approaches the capacity of a road (or of the intersections along the road), extreme traffic congestion sets in. When vehicles are fully stopped for periods of time, this is colloquially known as a traffic jam or traffic snarl-up. Traffic congestion can lead to drivers becoming frustrated and engaging in road rage.

Causes

Traffic congestion occurs when a volume of traffic or modal split generates demand for space greater than the available road capacity; this point is commonly termed saturation. There are a number of specific circumstances which cause or aggravate congestion; most of them reduce the capacity of a road at a given point or over a certain length, or increase the number of vehicles required for a given volume of people or goods. About half of U.S. traffic congestion is recurring, and is attributed to sheer weight of traffic; most of the rest is attributed to traffic incidents, road work and weather events.

Ontario Highway 401

King's Highway 401, commonly referred to as Highway 401 and also known by its official name as the Macdonald–Cartier Freeway or colloquially as the four-oh-one, is a 400-series highway in the Canadian province of Ontario. It stretches 828.0 kilometres (514.5 mi) from Windsor to the Quebec border. The part of Highway 401 that passes through Toronto is the busiest highway in the world, and one of the widest. Together with Quebec Autoroute 20, it forms the road transportation backbone of the Quebec City–Windsor Corridor, along which over half of Canada's population resides and is also a Core Route in the National Highway System of Canada. The entire route is maintained by the Ministry of Transportation of Ontario (MTO) and patrolled by the Ontario Provincial Police. The posted speed limit is 100 km/h (62 mph) throughout its length, unless posted otherwise.