Level crossing in the context of Hoylake

A stop sign is a traffic sign designed to notify drivers that they must come to a complete stop and make sure the intersection (or railroad crossing) is safely clear of vehicles and pedestrians before continuing past the sign. In many countries, the sign is a red octagon with the word STOP, in either English, the national language of that particular country, or both, displayed in white or yellow. The Vienna Convention on Road Signs and Signals also allows an alternative version: a red circle with a red inverted triangle with either a white or yellow background, and a black or dark blue STOP. Some countries may also use other types, such as Japan's inverted red triangle stop sign. Particular regulations regarding appearance, installation, and compliance with the signs vary by some jurisdictions.

In civil engineering (and more specifically, highway or railway engineering), grade separation is a method of aligning a junction of two or more surface transport axes at different heights (grades) so that they will not disrupt the traffic flow on other transit routes when they cross each other. The composition of such transport axes does not have to be uniform; it can consist of a mixture of roads, footpaths, railways, canals, or airport runways. Bridges (or overpasses, also called flyovers), tunnels (or underpasses), or a combination of both can be built at a junction to achieve the needed grade separation.

In North America, a grade-separated junction may be referred to as a grade separation or as an interchange – in contrast with an intersection, at-grade, a diamond crossing or a level crossing, which are not grade-separated.

An elevated railway or elevated train (also known as an el train or el for short) is a railway with the tracks above street level on a viaduct or other elevated structure (usually constructed from steel, cast iron, concrete, or bricks). The railway may be a broad-gauge, standard-gauge or narrow-gauge railway, rapid transit, light rail, monorail, or a suspension railway. Elevated railways are normally found in urban areas that would otherwise require impracticably many level crossings. Usually, the tracks of elevated railways that run on steel viaducts can be seen from street level.

A crossbuck is a traffic sign used to indicate a level railway crossing. It is composed of two slats of wood or metal of equal length, fastened together on a pole in a saltire formation (resembling the letter X). Crossbucks are often supplemented by electrical warnings of flashing lights, a bell, and/or a boom barrier that descends to block the road and prevent traffic from crossing the tracks.

A limited-access road, known by various terms worldwide, including limited-access highway, partial controlled-access highway, and expressway, is a highway or arterial road for high-speed traffic which has many or most characteristics of a controlled-access highway (also known as a freeway or motorway), including limited or no access to adjacent property; some degree of separation of opposing traffic flow (often being dual carriageways); use of grade separated interchanges to some extent; prohibition of slow modes of transport, such as bicycles, horse-drawn vehicles or ridden horses, or self-propelled agricultural machines; and very few or no intersecting cross-streets or level crossings. The degree of isolation from local traffic allowed varies between countries and regions. The precise definition of these terms varies by jurisdiction.