Cycling in England and Wales is quite good for leisure routes, with a national network developed and signposted by Sustrans. Some routes follow former railways. There are also some regional routes, and byways. Some roads will also have dedicated cycle lanes, especially in major urban centres.
A separate guide exists at Cycling in Scotland for an overview of touring and mountain biking in Scotland.
The bicycle of choice for most cyclists in Britain is the hybrid - they have the comfort and practicality of a city bike combined with the performance (multi-speed gearing) and ruggedness of a mountain bike. Conventional mountain bikes and single-speed roadsters are also common, and folding bikes are becoming more popular in major cities. Expect to pay £100 or more for a basic model hybrid bike.
Bicycles are permitted on some trains, depending on the operator. Commuter trains generally allow folding bicycles only, some regional trains may have a rack that can carry 2-3 bicycles, while many intercity trains have a baggage car that can hold many bikes. Check with the operator beforehand. Bikes will almost always require a reservation: on some trains for free, some for a small charge (typically half the adult fare) whilst others will require a full-fare ticket. Reservations can be made over the phone (via National Rail or via the train operator), or at the station ticket office. Long-distance coaches also allow bicycles, although again they must be reserved and there may be a surcharge.
If you are considering touring in the United Kingdom, it's worth considering buying the maps and guides produced by Sustrans to accompany the national routes they have helped develop. The routes can be found on Open Cycle Map, but Sustrans' guides are helpful for nearby places to stay or visit. See also Cycling in Scotland for an overview of touring and mountain biking.
CycleStreets. A national journey planner for cyclists, available online as well as an app for Android, iPhone and Windows Phone. Free to use and download 2016-04-28
There are some specific rules for cyclists in the UK's Highway Code, but other traffic rules are equally applicable.
It is a legal requirement to have a rear reflector, pedal reflectors and a bell, and working front & rear lights which must be used during the night or hours of darkness Reflective clothing is always a good idea at night, as well as making your more visible in the day.
Cycling is banned on all motorways (M roads), and primary roads designated as motorway (e.g. the A1 (M)). Cycling can be forbidden on stretches of "A" roads, such as Hindhead Tunnel on the A3: these will be signposted. It is also illegal to cycle on a pavement unless it is marked as a cycle route. This is punishable by a fine, although police will often just tell a cyclist to get off the pavement and are likely to ignore young children cycling slowly on the pavement. Certain footpaths also restrict cyclists or require them to dismount.
When cycling on roads, you must ride on the left with other vehicles. Traffic signs and lights still apply, and it is illegal to jump through a red light as for motorists. Advance stop lines at traffic lights, where provided, allow cyclists to wait ahead of other traffic at red lights. In practice, many car drivers ignore this and occupy the cycle space when waiting at lights.
Although as of 2018, there was no mandatory helmet requirement for cyclists in England and Wales, their use by cyclists of any age is indicated in the highway code, along with appropriate clothing (such as reflective high visibility bands at night or in poor weather).
Urban cycling varies city-to-city. Most cities have designated cycle lanes in the road, although these are routinely ignored by drivers and are often shared with buses, motorcycles and taxis. Some major roads will have split <abbr title="sidewalks/footpaths">'pavements'</abbr> for pedestrians and cyclists, whilst other times cyclists are expected to ride in the traffic. This can be dangerous if you're not a skilled cyclist and general traffic rules should be adhered to. You will easily find designated bike-parking areas with bicycle racks, which are almost always free to use. Carry a good lock with you as bike theft is common.
Cycling is good in some cities, especially Oxford and Cambridge. London have a network of cycle routes, although they are not as safe or pleasant as a city like Amsterdam. In general, UK city cycling is well below average for Europe. By contrast, rural cycling can be a pleasure.
In a few urban centres (such as Milton Keynes) the "cycle lane" can be effectively grade-separated from the highway network entirely, whereas in others the cycle lane is either on the sidewalk, or in the main carriageway.
In some areas, you can also use a canal towpath, or riverside path as a cycle lane, where it's allowed it's a quieter alternative to congested urban streets.
In London, Santander Cycles - sometimes called "Boris Bikes" after the former Mayor of London - provides a network of approximately 8,000 bicycles and 570 docking stations across the central area, covering an area from White City in the west to the Docklands in the east. The scheme is available to walk-up users and charges a daily fee. Users can return their bicycle to any docking station on the network. Copycat schemes have been frustratingly slow to materialise elsewhere, though Liverpool's Citybike seems to be leading the charge. Otherwise, private bike rental shops are present in most towns and cities and in some scenic areas.
Local city buses and regional buses don't allow full-size bikes but some operators may permit folding bicycles. If a bus is quiet then it's often down to the driver's discretion. Rapid transit systems also have varying bicycle policies e.g. London Underground allows folding bicycles at all times and conventional bicycles (on some parts of the network) outside of peak hours as long as the train isn't crowded.
England and Wales have some options for off-road, or mountain biking. However in some areas (such as the South Downs), or on certain routes cycle activities may be curtailed or prohibited to prevent damages to a specific ecosystem from cumulative erosion.
In England and Wales, there are many public bridleways across private land. The public have always had the right to walk or ride a horse on a public bridleway and in 1968 this right was extended to include cycling, but without requiring bridleways to be modified for cycling - do not be surprised if you have to carry your bike for a section. Public bridleways are shown on ordnance survey maps, and are usually marked with signs at roads.