question: Why does the UK have peak and off-peak train tickets?
comment: Probably to spread out the amount of people during peak hours. Those that can start later will take a later train to work and thus pay less. So it's to ease rush hour.
passages: Interventions to address these gaps are themselves divided into 16 options.
  
  Unless otherwise stated the peak-hour trains comprise those arriving in London between 7 and 10am ("high peak" between 8 and 9) and leaving between 4 and 7pm (high peak between 5 and 6); the hours on either side of the high peak are known as the "shoulder peak".
  
  Section::::Gaps and options.:Gap A (peak demand and network capacity) and Options 1 through 3, with sub-options.
   As the name implies, the ticket is generally intended for use outside peak times. Typically train companies prevent use of this type of ticket during key commuting hours of weekday mornings and early evening, especially for services beginning or terminating in London, at which times higher fares may be charged. 
   Due to the increase in passenger numbers and the prospect of high speed rail both within Great Britain and connecting to Europe, this period has been called the start of a new Golden Age of rail travel. However quickly increasing passenger numbers have meant many trains are very crowded at peak times. Peak-time fares have increased by over 200% (since privatisation) to deter people from travelling at these times, whereas the price of advance tickets has halved in the same period.
  
  Section::::Government policy.
  
  Section::::Government policy.:Reform under the Labour government (1997–2010).
   BULLET::::- (originally Ashburys for Belle Vue before a station was built at Belle Vue on the Bredbury and Romiley line in the 1980s) serves the Openshaw and Beswick areas
  
  BULLET::::- (district of Hyde)
  
  BULLET::::- (district of Hyde)
  
  "Glossop branch:"
  
  "Hadfield branch:"
  
  The same train serves Glossop and Hadfield via one of three routings:
  
  During the autumn "leaf fall" timetable this pattern is modified so that the morning rush hour pattern is extended to about midday and the evening rush hour pattern starts as soon as the morning rush hour pattern finishes.
   Special "excursion" cheap-day tickets were first issued in May 1849 and season tickets in 1851. Until 1869 most revenue came from second-class passengers but the volume of third-class passengers grew to the extent that second-class facilities were withdrawn in 1912. The Cheap Trains Act 1883 resulted in the provision of workmen's trains at special low fares at certain times of the day.
   In certain cases where there was exceptionally low usage the train service was reduced to a bare minimum, but the service was not formally closed, avoiding the costs associated with closure. In some cases the service was reduced to one train a week, and in one direction only.
   All of the schemes were retained after privatisation, despite some threats of abolition. By generating extra income at off-peak times when trains are generally less crowded, they offer a potential commercial benefit for the TOCs.
   BULLET::::- Gap G - between future services on the Hastings route and currently envisaged services.
  
  Interventions to address these gaps are themselves divided into 16 options.
  
  Unless otherwise stated the peak-hour trains comprise those arriving in London between 7 and 10am ("high peak" between 8 and 9) and leaving between 4 and 7pm (high peak between 5 and 6); the hours on either side of the high peak are known as the "shoulder peak".
  
  Section::::Gaps and options.:Gap A (peak demand and network capacity) and Options 1 through 6.
   From 1 April 2019, Network Rail introduced a new 'more detailed and precise set of measures...The official measure of punctuality used up till now, known as the public performance measure (PPM), considers trains to be punctual if they are five or 10 minutes after schedule, for short and long-distance trains are respectively, at their destination. The new measures will report cancellations and the proportion of trains arriving to the minute at every station on the timetable, known as a ‘station stop’, where technology allows...'
  
  Section::::Criticisms.
   As of 2007, these discounts are still available. When the Network Card changed to the more restrictive "Network Railcard" format, with children receiving a 60% discount subject to a minimum £1.00 fare (rather than a £1.00 flat fare in all cases) and adults being subject to a £10.00 minimum fare on weekdays, the Gold Card's conditions remained the same as before, and have not changed since. First Class Supplement tickets for Gold Card holders costing £5.00 for adults and £3.00 for accompanying children were abolished from 2016, in lieu of which the Gold Card discount became available on first class tickets. At that time, the discounts became available from 09:30 instead of 10:00 on weekdays, the area of operation extended well into the West Midlands, and Virgin Trains and Virgin Trains East Coast (now LNER) withdrew from accepting Gold Card discounts. CrossCountry continues to accept them based on the old area, with a northern limit of Banbury.
   As part of the new Franchise Agreement agreed in 2016, the Department for Transport required the introduction of a penalty fare scheme across 60% of the Northern network by the end of 2019 and across the entire network by the end of 2022. The scheme aimed to reduce ticketless travel to less than 4.3% by March 2020 and 3.2% by March 2025. In April 2018, a penalty fare scheme under the Railways (Penalty Fares) Regulations 2018 commenced to encourage passengers to purchase a ticket before boarding trains.
   Off-Peak Day Return ticket
  
  An off-peak day return ticket is the name given to a cheap day return railway ticket (a substantially reduced two-way fare for off-peak travel) after pricing by time of travel was introduced on the British railway network in the 1960s.
   During the early 1970s, some of offered a series of small, localised travel promotions for people of or near retirement age. The London Midland and Southern regions were particularly active in this, although other examples existed elsewhere. These promotions were characterised by restricted validity and geographical availability. For example, one Southern Region scheme introduced in 1970 offered pensioners half-price travel at off-peak times on Tuesdays, Wednesdays and Thursdays only, for journeys from a set list of around twenty stations, upon production of their pension book (to confirm their eligibility).
   The standard discount on the full adult fare is 34%, to the nearest £0.05; virtually all ticket types qualify for a discount. No discounts are available for accompanying children. In addition, a "minimum fare" applies before 10:00 Monday to Friday; this used to be £8.00 for a single ticket and discounted returns, and £16.00 for full-price return ticket types. However, from 17 May 2009 the minimum fare changed to £12 regardless of whether it was a single or a return ticket bought. Although most discounted tickets become available after 09:30, the minimum fare of £12 is still charged until 10:00. During July and August the minimum fare rule does not apply. Tickets issued at the minimum fare bear the wording MIN.
   Daily tickets fell into four categories: Peak 'Anytime', Off Peak, Super Off Peak and Advance (pre-booked, long distance). These were broken down into whether the user requires a "Single", "Return" (valid for one calendar month) or a "Day Return."
  
  Section::::Ticketing.:Smartcards.
  
  Oyster pay-as-you-go could be used on services within Greater London. Oyster cards holding season tickets were accepted within the London Travelcard area, in the same way as normal paper Travelcards and season tickets.
   BULLET::::- As only the time at the terminating station is recorded, a train could have been late at some of its intermediate stations, affecting passengers alighting at those stops, and this would not be a PPM fail. This is particularly the case for timetables with 'backloading', or 'padding', which is when extra minutes are built into the final leg of the journey as 'catch-up' time. While time at the terminus is important for morning commuter trains into a city, when most passengers alight at the terminus, for inter-city trains, cross-country trains, and evening commuter trains out of a city, it is irrelevant to most passengers, who will alight at different points along the journey.
   As part of the National Concessionary Pass scheme for buses, authorities have the option of adding extra concessions to their area for the benefit of local residents. Transport for West Midlands, as part of their options, allow residents in the West Midlands (County), as defined by Dudley, Wolverhampton, Walsall, Sandwell, Birmingham, Solihull and Coventry Council areas, to use local rail services (within the West Midlands) using their National Concessionary Passes for free after 09.30 on weekdays and all day weekends/Bank Holidays. No separate ticket is needed.
   From September 1987, more than 12 months before the Annual Season Ticket Holder's Railcard was discontinued, a similar scheme began in the Network SouthEast area of London and southeast England. Annual season tickets issued for journeys within this area became known as Gold Cards, and the season ticket functioned as a Railcard giving various benefits which were broadly the same as those received by holders of the former Network Card: 34% discounts for themselves and up to three accompanying adults on most off-peak fares, £1.00 flat-fare tickets for children, and First Class Supplement upgrades. The same time restriction (after 10.00am on weekdays; all day at weekends and on public holidays) also applied. When a Gold Card holder is travelling on the route covered by their Gold Card with accompanying adults or children, a separate discounted ticket does "not" have to be purchased by the Gold Card holder in order to secure the relevant discounts for the other members of the group.
   For trains in the Netherlands there is an off-peak discount available, giving a 40% discount. Its validity starts at 9am (until 4am the next morning) on weekdays, and all day at weekends and in July and August. In the case of a group of up to four people, all get the discount even if only one has a pass.
   It was not until 2 August 1880, when the Statutes (Definition of Time) Act received the Royal Assent, that a unified standard time for the whole of Great Britain achieved legal status.
  
  Section::::Introduction of railway time.:United States of America.
   For other Railcards, other restrictions apply; for example, the Family Railcard and Network Railcard cannot be used for peak journeys within London and south-east England.
  
  Section::::Traffic management by country.:United States.
   The times at which an Off-Peak fare is valid are set by the relevant train operator according to various factors, from levels of peak demand on the route in question to revenue maximisation. The specific details are given by referring to the two-digit 'validity code' assigned to the fare. The simplest apply a simple blanket time period to both outward and return journeys; more complex validity codes may apply different restrictions to outward and return journeys, or combine general validity periods with train-specific exemptions or exclusions.
   From Monday to Saturday there are six trains per hour in both directions, with services running every ten minutes using a single Class 139 railcar, with the second Class 139 as a spare. An end-to-end journey on the branch line takes three minutes. Weekday services commence at around 0600 and draw to a close shortly after midnight, with Saturday services starting later and ending earlier.
  
  On Sundays, there are four trains per hour operating every fifteen minutes in both directions, with services commencing around 1000 and ending around 2000.
  
  Section::::Performance.
   In mid-2006, First Capital Connect introduced evening peak-time fares for northbound travel out of London as a franchise commitment with the Department for Transport. Previously passengers with an off-peak travelcard could travel on any train after the morning peak had finished at 09:30. Now passengers may no longer use an off-peak ticket for trains leaving London stations between 16:30 and 19:00. Passengers using these peak-hour trains must pay an additional charge to travel. The evening peak restriction does not affect southbound travel. This was introduced due to severe peak-time overcrowding.
   In the United Kingdom, a cheap day return ticket is a reduced fare charged to passengers who make their outward and return trips on the same day, usually within specified hours of the day that do not coincide with peak travel periods, such as rush hour. On British Rail services, a cheap day return was valid for off-peak services, meaning, for instance, that London-bound trains which arrived in the capital after 10am were the earliest morning trains available to passengers holding a cheap day return ticket.
  