In public transportation, schedule adherence or on-time performance refers to the level of success of the service (such as a bus or train) remaining on the published schedule. On time performance, sometimes referred to as on time running, is normally expressed as a percentage, with a higher percentage meaning more vehicles are on time. The level of on time performance for many transport systems is a very important measure of the effectiveness of the system.
On time performance is a measure of the ability of transport services to be on time. Almost all formal transportation systems have timetables, which describe when vehicles are to arrive at scheduled stops. Transport services have a higher utility where services run on time, as anyone planning on making use of the service can align their activities with that of the transport system. On time performance is particularly important where services are infrequent, and people need to plan to meet services.
The ability of different transport modes to meet on time performance statistics depends on the degree to which they are affected by external factors. For example, rail services often operate on a separated right of way, and so are not affected by road congestion. Buses, unless they are separated from road traffic, will be heavily affected by congestion.
To calculate the percentage of vehicles on time, comparison is needed with the timetable. A comparison is often completed for arrival time rather than departure time, but both are common. Departure times are normally more on-time than arrival times, as incidents and breakdowns occur that reduce the on time performance. When the comparison is made between the timetable, and the actual arrival or departure time, a rule is applied to determine how much of a deviation is permitted. For example, if a bus is 4 minutes 20 seconds late, a rules may be applied that a bus is only late when later than 5 minutes, so this service would be counted as on time. The choice of threshold for lateness is an important one, with a low threshold resulting in a lower on time performance statistic. A high threshold will result in more services on time, but may result in the managing corporation or government body being accused on not reporting correctly.
Passengers can be updated on the movement of transport vehicles with passenger information systems. These systems display the arrival time of vehicles to stops, stations or airports, and typical information displayed is the time in minutes to the next scheduled arrival. Some of these systems have been extended to include apps to show the movement of trains/buses/planes/ferries. Where services are delayed, more information can be provided, such as alternative transport options, or estimated time till services resume.
A small number of transport systems operate on the principle of go-when-full. This type of transport system will not have any meaningful measure of on time performance.
Airlines are closely monitored on their on time performance. Numerous websites exist for reporting on punctuality for airlines, often operated by government departments. [1] Iraqi Airways, an airline, uses a rule that aircraft that depart within 15 minutes of scheduled departure are on time. [2] The 15 minutes rules for on time performance is commonly applied throughout the airline industry. [3] Airlines typically perform well when their on time performance reaches 90%. [4] OAG and Cirium regularly publish airline on time performance rankings and data. [5] in 2022, Cirium named Azul Airlines the most on-time airline. [6] Cirium's 2023 most on-time airline was Avianca. [7]
On time performance for aircraft is simple to calculate as aircraft depart and arrive at airports, and these are clear points to complete the on-time performance calculation.
On bus services, performance measures are substantially less clear for bus services. Performance can be calculated for each and every stop. But another method that saves resources is to calculate on time performance for only the start and end of the bus route, which can produce meaningful statistics. One problem with this method is where very large stops or interchanges are not at the start and end of the bus journey, but in the middle, and the start and end of the route are bus depots or other small stops for which on time performance statistics are not as important. In this situation on time performance may be calculated at the major interchange, rather than the start and end.
Bus routes are frequently late, given buses mix with road traffic. Bus rapid transit is a bus-based mass transit system, where road infrastructure has been specifically constructed to allow better on time performance, and more frequent and high-speed services. This type of bus system is far less exposed to problem of low on time performance statistics than regular bus services. Trying to get to the school on time can be a big hassle for drivers. This results in 76 percent of schools in Ontario and Quebec to have late departures by chance not choice.
Light rail, whilst being a rail system, can be exposed to problems with poor on time performance. This is especially the case where rail service operates in the middle of congested roads, and where a light rail system has a separate right of way the on-time performance will be better.
Users of transport systems often use several transport modes to complete a journey. They will change transport modes at a transport hub, and all transport modes have some kind of transport hub.
On time performance is important to interchanges. Where on time performance is poor, passengers or goods may miss a connection, and so be forced to wait. In some cases, the transit time allowed from one transport mode to another may be very small, and so any lateness can result in services being missed. Where services are infrequent, such as a long-distance train trip, or a flight, then the consequences of late services can be high. Transport systems that exist to deliver passengers and services to interchanges should be particularly concerned with achieving a good on time performance.
Typically on time performance is measured by comparing each service with its schedule. [8] A threshold is chosen for how late a service can be before it is determined to be late.
on-time Performance |
| (1) |
The scale of delays are often calculated in delay minutes. [9] A delay minute is the number of minutes a service is delayed multiplied by the number of passengers on board the transport vehicle.
passenger delay minutes |
| (2) |
Network Rail, a large rail infrastructure provider in the UK, uses passenger delay minutes as a mechanism to reward and punish for services being on time and late respectively. [10] Using delay minutes as a measure allows for comparisons between heavily loaded large transport vehicles, and much smaller or lightly loaded vehicles. The economic cost of a large transport vehicle being delayed is much greater than a service that is almost empty.
There are many factors that can affect on-time performance. [11] Depending on the situation, the service may face regular delays or a service that usually performs on time may be occasionally behind schedule. Some of these factors include:
The effect of delays to a transport system are normally calculated as costs in dollars, either to the passengers, or to the transport provider. The transport provider will incur costs of the additional use of the vehicle, crew costs, and fuel. [15] In many cases the cost is calculated as a dollar value per minute. The total cost of delays for an entire transport system for one year can be very large. [16]
In many publications the effect of poor on time performance is equated to lost money. As passengers are delayed, this delay is equated to dollars, and this is the amount that is lost. Calculations are performed for the total amount "lost" per year for different countries, for example, for the US it was estimated that the cost to the country was $32.9 billion in 2007. [17] The total amount of cost per country per year can be very large.
An economic cost is calculated through the following formula:
Economic cost |
| (3) |
The delay cost per minute is calculated as the addition of direct costs to a service provider, and the economic cost to passengers through lost time. [18] This is:
Delay cost per minute |
| (4) |
The economic cost per minute for passengers is often expressed as a percentage of the average in the area. [18] For different transport modes the cost per minute may be different, as those using buses may have a lower income than those using trains.
Buses when late may experience a problem known as bus bunching. On some bus lines with a more frequent service, if one bus falls behind schedule passenger numbers waiting at bus stops may grow, required a longer layover time. One or more subsequent buses on the published schedule may pass these already cleared stops and have a nearly empty run, and may actually jump ahead of their scheduled time to the point that two or more buses are within close sight of one another. In some cases, one bus is able to pass another. [19] This phenomenon is sometimes known as clumping or bunching. [20] When this occurs, the even spacing of buses on the schedule may be severely disrupted, leading to extremely long waits for those attempting to catch a bus, and multiple buses arriving at once. [21] Bus bunching serves to reduce the effectiveness of buses as a transport mode.
Transit agencies often take the following measures in attempts to improve schedule adherence on their routes:
![]() | This article needs to be updated.(March 2016) |
The following chart shows some examples of real-world on-time performance. The figures are always (unless stated otherwise) per vehicle, not per customer.
Operator | Mode of transport | Period | < 1' | < 2' | < 3' | < 5' | < 10' | < 15' | < 20' | < 30' | Comments | Source |
---|---|---|---|---|---|---|---|---|---|---|---|---|
SBB | All passenger rail | 2014 | 87.7% | [26] | ||||||||
Freight | 77.2% | |||||||||||
ÖBB | All passenger rail | 2021 | 97% | [27] | ||||||||
NS | Passenger railway | 2019 | 91.9% | 92.6% | 97.7% | Measured at selected key stations | [28] | |||||
Amtrak | Passenger Railway | 2008–2018 (average) | 77% | For trip length <250 miles train is late if >10 min | [29] | |||||||
Network Rail | National Railway | 2014 | 89.3% | Commuter services are late >5 min, intercity >10 min | [30] | |||||||
Taiwan High Speed Rail | High Speed Rail | 2013 | 99.44% | [31] | ||||||||
Lufthansa | All flights | 2014 | 84.7% | [32] | ||||||||
Qantas | Domestic Air Travel | 2015 | 88.6% | [33] | ||||||||
Cathay Pacific | International Air Travel | 2014 | 70.7% | [34] | ||||||||
Yarra Trams | Trams | Jan 2016 | 86.7% | [35] | ||||||||
Hong Kong MTR | Metro (rail) | 2015 to October | 99.9% | The threshold for on time is high at 8 minutes | [36] | |||||||
GO Transit | Commuter Rail | 2014–15 Fiscal Year | 94% | [37] | ||||||||
Buses | 95% | |||||||||||
SMRT | Metro (rail) | FY 2014 | 92.6% | [38] | ||||||||
New York City Subway | Metro (rail) | 2018 | 65% | [39] | ||||||||
Personal Rapid Transit (PRT), also referred to as podcars or guided/railed taxis, is a public transport mode featuring small low-capacity automated vehicles operating on a network of specially built guideways. PRT is a type of automated guideway transit (AGT), a class of system which also includes larger vehicles all the way to small subway systems. In terms of routing, it tends towards personal public transport systems.
Light rail transit (LRT) is a form of passenger urban rail transit characterized by a combination of tram and rapid transit features. While its rolling stock is similar to that of a traditional tram, it operates at a higher capacity and speed and often on an exclusive right-of-way. In many cities, light rail transit systems more closely resemble, and are therefore indistinguishable from, traditional underground or at-grade subways and heavy-rail metros.
Bus rapid transit (BRT), also referred to as a busway or transitway, is a bus-based public transport system designed to have much more capacity, reliability and other quality features than a conventional bus system. Typically, a BRT system includes roadways that are dedicated to buses, and gives priority to buses at intersections where buses may interact with other traffic; alongside design features to reduce delays caused by passengers boarding or leaving buses, or paying fares. BRT aims to combine the capacity and speed of a light rail transit (LRT) or mass rapid transit (MRT) system with the flexibility, lower cost and simplicity of a bus system.
The Metro Blue Line is a 12-mile (19.3 km) light rail line in Hennepin County, Minnesota, that is part of the Metro network. It travels from downtown Minneapolis to Minneapolis–Saint Paul International Airport and the southern suburb of Bloomington. Formerly the Hiawatha Line prior to May 2013, the line was originally named after the Milwaukee Road's Hiawatha passenger train and Hiawatha Avenue, reusing infrastructure from the former and running parallel to the latter for a portion of the route. The line opened June 26, 2004, and was the first light rail service in Minnesota. An extension, Bottineau LRT, is planned to open in 2028.
Intermodal passenger transport, also called mixed-mode commuting, involves using two or more modes of transportation in a journey. Mixed-mode commuting is often used to combine the strengths of various transportation options. A major goal of modern intermodal passenger transport is to reduce dependence on the automobile as the major mode of ground transportation and increase use of public transport. To assist the traveller, various intermodal journey planners such as Rome2rio and Google Transit have been devised to help travellers plan and schedule their journey.
The Sacramento Regional Transit District, commonly referred to as SacRT, is the agency responsible for public transportation in the Sacramento, California area. It was established on April 1, 1973, as a result of the acquisition of the Sacramento Transit Authority. In addition to operating over 81 bus routes with connecting bus service in the Sacramento area covering 438 square miles (1,134.4 km2), SacRT also operates a large light rail system, which ranks currently as the sixteenth busiest light rail system in the United States. In 2022, the system had a ridership of 9,314,400, or about 51,800 per weekday as of the third quarter of 2023.
An intercity bus service or intercity coach service, also called a long-distance, express, over-the-road, commercial, long-haul, or highway bus or coach service, is a public transport service using coaches to carry passengers significant distances between different cities, towns, or other populated areas. Unlike a transit bus service, which has frequent stops throughout a city or town, an intercity bus service generally has a single stop at one location in or near a city, and travels long distances without stopping at all. Intercity bus services may be operated by government agencies or private industry, for profit and not for profit. Intercity coach travel can serve areas or countries with no train services, or may be set up to compete with trains by providing a more flexible or cheaper alternative.
In public transport, a request stop, flag stop, or whistle stop is a stop or station at which buses or trains, respectively, stop only on request; that is, only if there are passengers or freight to be picked up or dropped off. In this way, stops with low passenger counts can be incorporated into a route without introducing unnecessary delay. Vehicles may also save fuel by continuing through a station when there is no need to stop.
Transport in Sydney is provided by an extensive network of public transport operating modes including metro, train, bus, ferry and light rail, as well as an expansive network of roadways, cycleways and airports. According to the 2006 census, in terms of travel to work or study Sydney has the highest rate of public transport usage among the Australian capital cities of 26.3% with more than 80% of weekday trips to/from Central Sydney being made by public transport. According to the New South Wales State Plan, the state has Australia's largest public transport system. The public transport network is regulated by Transport for NSW.
London has an extensive and developed transport network which includes both public and private services. Journeys made by public transport systems account for 37% of London's journeys while private services accounted for 36% of journeys, walking 24% and cycling 2%,according to numbers from 2017. London's public transport network serves as the central hub for the United Kingdom in rail, air and road transport.
A passenger information system, or passenger information display system, is an automated system for supplying users of public transport with information about the nature and the state of a public transport service through visual, voice or other media. It is also known as a customer information system or an operational information system. Among the information provided by such systems, a distinction can be drawn between:
A transport hub is a place where passengers and cargo are exchanged between vehicles and/or between transport modes. Public transport hubs include railway stations, rapid transit stations, bus stops, tram stops, airports and ferry slips. Freight hubs include classification yards, airports, seaports and truck terminals, or combinations of these. For private transport by car, the parking lot functions as a unimodal hub.
Ion, stylized as ION, is an integrated public transportation network in the Regional Municipality of Waterloo in Ontario, Canada. It is operated by Keolis and is part of the Grand River Transit (GRT) system, partially replacing GRT's Route 200 iXpress bus service. The section of the bus route serving Cambridge has been renamed "Ion Bus", and renumbered as 302. The first phase commenced operations on June 21, 2019, between the north end of Waterloo and the south end of Kitchener. A future extension of light rail to the downtown Galt area of Cambridge is planned but construction may not begin on that line until 2028.
In scheduled transportation, a layover is a point where a vehicle stops, with passengers possibly changing vehicles. In public transit, this typically takes a few minutes at a trip terminal. For air travel, where layovers are longer, passengers will exit the vehicle and wait in the terminal, often to board another vehicle traveling elsewhere.
Public transport bus services are generally based on regular operation of transit buses along a route calling at agreed bus stops according to a published public transport timetable.
In transportation, dwell time or terminal dwell time refers to the time a vehicle such as a public transit bus or train spends at a scheduled stop without moving. Typically, this time is spent boarding or deboarding passengers, but it may also be spent waiting for traffic ahead to clear, trying to merge into parallel traffic, or idling time in order to get back on schedule. Dwell time is one common measure of efficiency in public transport, with shorter dwell times being universally desirable.
Public transport is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typically managed on a schedule, operated on established routes, and that may charge a posted fee for each trip. There is no rigid definition of which kinds of transport are included, and air travel is often not thought of when discussing public transport—dictionaries use wording like "buses, trains, etc." Examples of public transport include city buses, trolleybuses, trams and passenger trains, rapid transit and ferries. Public transport between cities is dominated by airlines, coaches, and intercity rail. High-speed rail networks are being developed in many parts of the world.
A crush load is a level of passenger loading in a transport vehicle which is so high that passengers are "crushed" against one another. It represents an extreme form of passenger loading, and normally considered to be representative of a system with serious capacity limitations. Crush loads result from too many passengers within a vehicle designed for a much smaller number. Crush loaded trains or buses are so heavily loaded that for most passengers physical contact with several other nearby passengers is impossible to avoid.
Schedule padding—sometimes called simply padding, or recovery time—is some amount of 'additional' time added to part or all of a schedule, in excess of the expected duration, that allows it to be resilient to anticipated delays and increase the chance that the published schedule will be met. In some cases, excessive padding may be intentionally added to make it unlikely that the schedule won't be met, or to prefabricate an earlier-than-scheduled completion. Padding may have only a temporary positive impact, and many clients perceive this as a deceptive strategy.
Route capacity is the maximum number of vehicles, people, or amount of freight than can travel a given route in a given amount of time, usually an hour. It may be limited by the worst bottleneck in the system, such as a stretch of road with fewer lanes. Air traffic route capacity is affected by weather. For a metro or a light rail system, route capacity is generally the capacity of each vehicle, times the number of vehicles per train, times the number of trains per hour (tph). In this way, route capacity is highly dependent on headway. Beyond this mathematical theory, capacity may be influenced by other factors such as slow zones, single-tracked areas, and infrastructure limitations, e.g. to useful train lengths.