"An intersection or an at-grade junction is a junction where two or more roads converge, diverge, meet or cross at the same height."
Design of crossroads, junctions, roundabouts and other road intersections that allow vehicles and pedestrians to safely cross each other.
Traffic volume studies: This involves measuring the number of vehicles passing through an intersection over a specific period. Traffic volume studies help in determining the design and layout of the intersection, including the number of lanes and signal phasing.
Traffic safety: Traffic safety concepts are fundamental when designing intersections. It involves understanding safety measures such as pedestrian safety, vehicle safety, and cyclist safety.
Traffic control devices: Traffic signals, signs, and markings are essential components of intersection design. They regulate and control the movement of vehicles, pedestrians, and cyclists.
Traffic signal phasing: Signal phasing is the sequence of signal indications that allow various movements to occur in a coordinated and safe manner. It is essential to understand how signal phasing works to design an efficient intersection.
Traffic capacity analysis: This involves analyzing the intersection's capacity to handle the prevailing traffic volumes. It can help determine the appropriate number of lanes, signalization, and other design features.
Turning movements: Turning movements involve understanding the types of turns vehicles, pedestrians, and cyclists take at intersections. It is necessary to determine the appropriate lane widths, number of turn lanes, and signalization to accommodate these movements.
Intersection layout: Intersection layout involves selecting the best design for a particular location, including the number of turning lanes, approach angles, and lane widths.
Geometric design: Geometric design involves ensuring the intersection's physical features conform to specific standards and guidelines, including sight distance, horizontal and vertical curves, and intersection skew.
Bicycle and pedestrian accommodations: Designing for bicyclists and pedestrians involves understanding and catering to their unique needs, such as bike lanes, crosswalks, and sidewalks.
Intelligent Transportation Systems (ITS): ITS refers to using technology to enhance transportation operations, including traffic signals, cameras, and other systems. They can aid in intersection design by facilitating traffic flow, reducing congestion, and improving safety.
T-Intersection: A T-junction with vehicles entering from one direction and exiting in only two directions.
Y-Intersection: An intersection where three roads meet, creating a Y shape, and vehicles can travel in three directions.
Four-Way Intersection: An intersection where four roads meet, creating a cross shape, and vehicles can travel in four directions.
Roundabout: A circular intersection where vehicles travel in one direction around a central island.
Traffic Circle: A circular intersection with a raised island acting as a roundabout at the center.
Cloverleaf: A type of intersection with two overlapping ramps in the form of a cloverleaf.
Diverging Diamond: A type of intersection where traffic is temporarily shifted to the opposite side of the road (on a bridge or overpass) to facilitate left turns.
Continuous Flow Intersection: An intersection where left-turn movements are performed prior to reaching the main intersection.
Displaced Left Turn Intersection: An intersection where left turns are made via a separate signalized intersection or a U-turn.
Median U-Turn Intersection: A type of intersection that eliminates the need for left turn lanes by requiring drivers to make a U-turn at a nearby median.
Jughandle Intersection: An intersection where vehicles exit the main thoroughfare to the right and then cross over, under, or through the cross street to turn left.
Restricted Crossing U-Turn Intersection: An intersection with two separate intersections for turning right and making a U-turn to turn left.
"...as opposed to an interchange, which uses bridges or tunnels to separate different roads."
"Major intersections are often delineated by gores..."
"...and may be classified by road segments, traffic controls, and lane design."
"This article primarily reflects practice in jurisdictions where vehicles are driven on the right."
"If not otherwise specified, 'right' and 'left' can be reversed to reflect jurisdictions where vehicles are driven on the left."