A counterflow lane, also known as a contraflow lane, is a lane in which traffic flows in the opposite direction as the surrounding lanes. Contraflow lanes are frequently utilized on one-way roadways for cyclists or bus rapid transit. They can also be used to reduce congestion by giving drivers an alternative route when main roads are blocked by events such as parades or demonstrations.
Traffic counterflow is the practice of directing both directions of traffic onto a single roadway at the same time, usually during special events or maintenance work that requires closing all lanes of traffic. It is common in countries where streets are designed with wide sidewalks, allowing people to walk in both directions simultaneously. Traffic countersubject to this practice will typically flow in alternating directions throughout the day.
Counterflows are often used by police officers to control traffic around schools and hospitals, though their use in other situations has been documented. In some cases, they are indicated by plastic flags attached to poles along the side of the road. When it is safe to do so, officers will move these flags from left to right to indicate the direction each lane should travel.
Counterflows are also commonly used by firefighters during emergency responses or when removing debris from roadways. Here, too, they use plastic flags attached to poles to indicate the direction each lane should travel.
A through lane, sometimes known as a through lane, is a traffic lane used for through traffic. These may be marked by arrows on the pavement pointing straight forward at junctions. An auxiliary lane is a lane that is used to segregate incoming, departing, or turning vehicles from through traffic. These are typically not marked but can be useful if there's no space elsewhere on the road. Through lanes allow drivers to bypass slower-moving or stopped vehicles in other lanes without having to stop or risk being blocked themselves.
Through lanes are commonly found in cities with large volumes of traffic, where splitting the stream allows faster-moving vehicles to pass the slower ones without interfering with the movements of others. The use of through lanes reduces congestion and increases travel speed. However they can also lead to increased risk of accident if not used properly. In some countries, such as Australia, India, and Singapore, they are required by law to be left empty when there is no through traffic so that emergency vehicles can break quickly through any queued up line of traffic.
In North America, through lanes are often designated by white lines on the road or yellow signs showing a white square with a red diagonal stripe across it. These markings are usually placed every 200 feet (60 m) or so along major routes to indicate which lanes are reserved for through traffic. They are used to inform drivers of the fastest route while avoiding congested areas.
A lane is a section of a highway (carriageway) that is allocated to be used by a single line of cars to manage and guide drivers and reduce traffic issues. The majority of public roadways (highways) have at least two lanes, one in each direction, divided by lane markers. A few roads may have only one lane in each direction, with the addition of center lines to indicate where drivers should not park themselves in between vehicles.
Lanes are usually distinguished from each other by color, shape, or some other physical feature. They can also be called "fast" or "slow" depending on how fast or slow moving vehicles are allowed in them. Lanes help drivers avoid collision with others vehicles and maintain a safe distance from the vehicle in front.
In order for motorists to change lanes safely they need to be aware of what's happening ahead in the other lanes. This awareness is increased by allowing more space between vehicles in adjacent lanes. It is important not to stop your vehicle in the middle of a lane, this could cause confusion as well as danger if another driver needs to turn into that lane soon after.
Traffic officers use the term "lane discipline" when referring to the act of drivers changing lanes appropriately. If there's no car in the next lane over, don't stop suddenly or leave too much space between you and the vehicle in front.
At junctions on one or more approaches, traffic control devices such as YIELD or STOP signs or traffic signals can be used to allocate the right-of-way. Roundabouts, sometimes known as little traffic circles, are another technique to award rights of way; we'll discuss them on page 2.
These devices are commonly called controls, but they also may be called signs, markings, or markers. The term "marker" is most often used for signs that are placed in advance of an intersection to indicate that a change is being made to the through movement from one route to another. For example, if a four-lane highway has two lanes for each direction with no center divider, then a marker would be placed before the intersection to indicate that drivers should use their left turn signal before making a left turn from either side of the road.
The word "control" is used most often to describe signs or signals that are placed after an intersection to indicate how a conflict should be resolved. For example, if a four-lane highway has two lanes for each direction with a center divide separating the two directions, then a control device would be placed after the intersection to indicate which direction should have priority when driving down the middle lane. These controls are usually placed in the center of the lane that is preferred by most drivers so that both directions can share the burden of traffic congestion. However, if there is no shared preference, the control may be placed before the intersection instead.