freeway-to-freeway interchanges

freeway-to-freeway interchanges are the most common type of expressway interchange. They are typically used where two freeways cross.

cloverleaf interchange

A cloverleaf interchange is a two-level interchange in which incoming and outgoing traffic on one freeway are able to cross over or under the other freeway. Cloverleaf interchanges are often used when there is limited space available for an interchange, and they can be found in both urban and rural areas.

stack interchange

In a stack interchange, also called a stacked interchange or a marriage stack, roads of two different levels (usually an expressway above and a local road below) cross without the use of ramps or overpasses. The crossing is accomplished by stacking one road above or below the other. Although uncommon in North America, they are commonplace in Europe (especially the United Kingdom), where they are often well signposted and lit.

directional interchange

A directional interchange is an interchange in which traffic is able to move between two freeways in one direction only. This type of interchange is typically found in urban areas, where space is limited.

freeway-to-arterial interchanges

freeway-to-arterial interchanges are the most common type of expressway interchange. This type of interchange is usually found on urban expressways and freeways where there is a high volume of traffic. This type of interchange allows for a smooth transition from the freeway to the arterial.

diamond interchange

The diamond interchange is the most basic type of freeway-to-arterial interchange. It typically consists of two loop ramps on each side of the freeway, as well as a pair of left-turn lanes on the arterial road. The loop ramps allow traffic to exit or enter the freeway, while the left-turn lanes provide access to side streets.

partial cloverleaf interchange

The first of the freeway-to-arterial interchanges is the partial cloverleaf interchange. In this configuration, direct connection is provided between the freeway and the arterial road for traffic traveling in one direction only. For traffic going in the opposite direction, a left turn movement must be made to reach the arterial road. Because of this, partial cloverleaf interchanges are not ideal for busy roads in which traffic is traveling in both directions.

trumpet interchange

A trumpet interchange is a type of freeway-to-arterial interchange where the off-ramp from the freeway forms a loop that merges with the on-ramp to the arterial. This configuration allows traffic to merge more gradually, which improves safety and helps reduce congestion.

arterial-to-arterial interchanges

at-grade intersection

At-grade intersection, also known as a signalized intersection or traffic light, is the most basic type of expressway interchange. It is an intersection where two or more roads meet at the same level, with traffic controlled by stop signs or traffic signals.

grade-separated intersection

In an arterial-to-arterial grade-separated intersection, the arterials are typically separated by a median or other physical barrier. This type of interchange is often used when one of the arterials is a freeway or expressway, and traffic volumes on both routes are high.