Cycles of all sorts

Segregated cycle facilities may consist of a separate road, track, path or lane that is designated for use by cyclists and from which motorised traffic is generally excluded. Segregated cycle facilities are distinct from facilities in which cyclists are integrated with other traffic (i.e., not separated from other traffic by class).

There are various types of cycle facility and different countries use differing, often legally defined, terms to distinguish them. In essence, segregated cycle facilities fall into two categories; "Off-road" and "On-road". In the United States, off-road unsurfaced trails are commonly called "bike trails" or "mountain-bike trails", while surfaced trails that are separate from roadways and which meet more rigorous standards for width, grade and accessibility are commonly called "bike paths." In the United Kingdom and some other places, the term "cycle path" is sometimes used as a blanket term for any off-road device. The term "designated bicycle lane" has been defined in at least one country (the USA) as a portion of the roadway or the shoulder which has been designated for use by bicyclists.

Caution is required when approaching discussions of the topic. Some of the claims and counter-claims regarding cycle facilities might be best interpreted as competing ideological doctrines rather than established engineering truths. The arguments have also been characterised in terms of a social custom or even taboo which reserves the roadway for motorised users.

The use of such devices has been a source of a great deal of controversy since the 1930s, as motor-vehicle use increased. Some commentators inaccurately use various terms interchangeably. In some cases this is done out of simple ignorance but in other cases this may result from deliberate attempts to confuse matters that involve serious accusations related to fatality, injury and legal culpability. Even the use of the word "facility" is controversial and is disputed.