An isochrone map in geography and urban planning is a map that depicts the area accessible from a point within a certain time threshold. [1] An isochrone (iso = equal, chrone = time) is defined as "a line drawn on a map connecting points at which something occurs or arrives at the same time". [2] In hydrology and transportation planning isochrone maps are commonly used to depict areas of equal travel time. The term is also used in cardiology [3] [4] [5] as a tool to visually detect abnormalities using body surface distribution. [6]
Early examples of Isochrone maps include the Galton's Isochronic Postal Charts and Isochronic Passage Charts of 1881 and 1882, [8] Bartholomew's Isochronic Distance Map and Chart first published 1889, [9] and Albrecht Penck's Isochronenkarte first published 1887. [10] Where as Galton and the Bartholomews published maps depicting the days or weeks it took to travel long distances, Albrecht further developed the idea to not only depict long distances and world travel but also smaller areas. Penck also created a series of maps that only depict the travel times of a certain transportation mode, for example rail transport. Isochrone maps are commonly used in the UK in connection with development control. [11] [12] [13] [14] Isochrones are currently typically computed by via generating shortest-path trees on network graphs, and then generating a convex hull around the accessible nodes. Increases in computation, data storage, and improvements in algorithms have facilitated the rapid generation of isochrones. [1] [15] Recent techniques in visualization include linking travel times to network edges to show the paths accessible from a point rather than show the area accessible from a point. [1]
Isochrone and related maps are used to show the time taken for runoff water within a drainage basin to reach a lake, reservoir or outlet, assuming constant and uniform effective rainfall. [16] [17] [18] [19] An early example of this method was demonstrated by Clark in 1945. [20]
Isochrone maps have been used in transportation planning since at least 1887. [21] [22] Isochrone maps in the context of transport planning are essentially maps of accessibility where travel time is used as the cost metric. Isochrone maps can be created for different modes of transportation, [23] e.g. foot, bicycle, motor vehicle. Put simply, the output of an isochrone map for transport will show how far (in distance) is reachable from a start point, including the parameter of time.
Such maps for private motor transport were widely used in a 1972 study into airport accessibility in Hampshire, South East England. [24] At that time, their use was disadvantaged by being time-consuming to create. [24]
The term isodapane map is used to refer to a map were the contour represent transportation cost instead of transportation time. [25]
Journey time websites have been built using mapping technologies and open data. [26] [27] Isochrones can be used by house hunters wishing to evaluate residential areas. [28] An isochrone map of the London Underground network was made available in 2007. [29]
Several digital tools exist which can generate isochrone maps.
openstreetmap-based solutions: [30]
GTFS-based solutions:
Proprietary data solutions:
Linear referencing, also called linear reference system or linear referencing system (LRS), is a method of spatial referencing in engineering and construction, in which the locations of physical features along a linear element are described in terms of measurements from a fixed point, such as a milestone along a road. Each feature is located by either a point or a line. If a segment of the linear element or route is changed, only those locations on the changed segment need to be updated. Linear referencing is suitable for management of data related to linear features like roads, railways, oil and gas transmission pipelines, power and data transmission lines, and rivers.
A GIS software program is a computer program to support the use of a geographic information system, providing the ability to create, store, manage, query, analyze, and visualize geographic data, that is, data representing phenomena for which location is important. The GIS software industry encompasses a broad range of commercial and open-source products that provide some or all of these capabilities within various information technology architectures.
The public transport accessibility level (PTAL) is a method sometimes used in United Kingdom transport planning to assess the access level of geographical areas to public transport.
OpenStreetMap is a website that uses an open geographic database which is updated and maintained by a community of volunteers via open collaboration. Contributors collect data from surveys, trace from aerial photo imagery or satellite imagery, and also import from other freely licensed geodata sources. OpenStreetMap is freely licensed under the Open Database License and as a result commonly used to make electronic maps, inform turn-by-turn navigation, assist in humanitarian aid and data visualisation. OpenStreetMap uses its own topology to store geographical features which can then be exported into other GIS file formats. The OpenStreetMap website itself is an online map, geodata search engine and editor.
QGIS is a geographic information system (GIS) software that is free and open-source. QGIS supports Windows, macOS, and Linux. It supports viewing, editing, printing, and analysis of geospatial data in a range of data formats. QGIS was previously also known as Quantum GIS.
In cartography and geographic information systems, rubbersheeting is a form of coordinate transformation that warps a vector dataset to match a known geographic space. This is most commonly needed when a dataset has systematic positional error, such as one digitized from a historical map of low accuracy. The mathematics and procedure are very similar to the georeferencing of raster images, and this term is occasionally used for that process as well, but image georegistration is an unambiguous term for the raster process.
Web mapping or an online mapping is the process of using, creating, and distributing maps on the World Wide Web, usually through the use of Web geographic information systems. A web map or an online map is both served and consumed, thus, web mapping is more than just web cartography, it is a service where consumers may choose what the map will show.
A transit map is a topological map in the form of a schematic diagram used to illustrate the routes and stations within a public transport system—whether this be bus, tram, rapid transit, commuter rail or ferry routes. Metro maps, subway maps, or tube maps of metropolitan railways are some common examples.
In urban planning, walkability is the accessibility of amenities by foot. It is based on the idea that urban spaces should be more than just transport corridors designed for maximum vehicle throughput. Instead, it should be relatively complete livable spaces that serve a variety of uses, users, and transportation modes and reduce the need for cars for travel.
A journey planner, trip planner, or route planner is a specialized search engine used to find an optimal means of travelling between two or more given locations, sometimes using more than one transport mode. Searches may be optimized on different criteria, for example fastest, shortest, fewest changes, cheapest. They may be constrained, for example, to leave or arrive at a certain time, to avoid certain waypoints, etc. A single journey may use a sequence of several modes of transport, meaning the system may know about public transport services as well as transport networks for private transportation. Trip planning or journey planning is sometimes distinguished from route planning, which is typically thought of as using private modes of transportation such as cycling, driving, or walking, normally using a single mode at a time. Trip or journey planning, in contrast, would make use of at least one public transport mode which operates according to published schedules; given that public transport services only depart at specific times, an algorithm must therefore not only find a path to a destination, but seek to optimize it so as to minimize the waiting time incurred for each leg. In European Standards such as Transmodel, trip planning is used specifically to describe the planning of a route for a passenger, to avoid confusion with the completely separate process of planning the operational journeys to be made by public transport vehicles on which such trips are made.
Caliper Corporation was founded in 1983 as a developer of mapping software and is headquartered in Newton, Massachusetts.
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.
GTFS or the General Transit Feed Specification defines a common data format for public transportation schedules and associated geographic information. GTFS contains only static or scheduled information about public transport services, and is sometimes known as GTFS Static or GTFS Schedule to distinguish it from the GTFS Realtime extension, which defines how information on the realtime status of services can be shared.
Mapbox is an American provider of custom online maps for websites and applications such as Foursquare, Lonely Planet, the Financial Times, The Weather Channel, Instacart, Strava and Snapchat. Since 2010, it has rapidly expanded the niche of custom maps, as a response to the limited choice offered by map providers such as Google Maps.
Vector tiles, tiled vectors or vectiles are packets of geographic data, packaged into pre-defined roughly-square shaped "tiles" for transfer over the web. This is an emerging method for delivering styled web maps, combining certain benefits of pre-rendered raster map tiles with vector map data. As with the widely used raster tiled web maps, map data is requested by a client as a set of "tiles" corresponding to square areas of land of a pre-defined size and location. Unlike raster tiled web maps, however, the server returns vector map data, which has been clipped to the boundaries of each tile, instead of a pre-rendered map image.
iD is a free software online editor for OpenStreetMap (OSM) geodata created in JavaScript and released in 2013. It is the most popular and the default editor on the main OSM page. iD's features include choosing custom aerial imagery and native support for Mapillary photos.
In transport planning, accessibility refers to a measure of the ease of reaching destinations or activities distributed in space, e.g. around a city or country. Accessibility is generally associated with a place of origin. A place with "high accessibility" is one from which many destinations can be reached or destinations can be reached with relative ease. "Low accessibility" implies that relatively few destinations can be reached for a given amount of time/effort/cost or that reaching destinations is more difficult or costly from that place.
Vector overlay is an operation in a geographic information system (GIS) for integrating two or more vector spatial data sets. Terms such as polygon overlay, map overlay, and topological overlay are often used synonymously, although they are not identical in the range of operations they include. Overlay has been one of the core elements of spatial analysis in GIS since its early development. Some overlay operations, especially Intersect and Union, are implemented in all GIS software and are used in a wide variety of analytical applications, while others are less common.
GTFS Realtime is an extension to GTFS, in which public transport agencies share real-time vehicle locations, arrival time predictions, and alerts such as detours and cancellations via Protocol Buffers web server.
Azure Maps is a suite of cloud-based, location-based services provided by Microsoft as part of the company's Azure platform. The platform provides geospatial and location-based services via REST APIs and software development kits (SDKs). The service is typically used to integrate maps or geospatial data into applications.