Isochrones/Isodistances

Basic principles

This web service calculates an isochrone/isodistance from a point and returns the geometry of the zone calculated.

Isochrones example

{
        "url":"https://api.geoconcept.com/EU/GCW/geoconcept-web/api/lbs/isochrone/v5.json",
        "type":"GET",
        "params": {
                "location": {
                        "sample":"2.321134,48.796575"
                },
                "distance": {
                        "sample":"1000"
                },
                "time": {
                        "sample":"60"
                },
                "method": {
                        "sample":"time"
                },
                "exclusions": {
                        "sample":""
                }
        }
}

Parameters / properties

Input

parameter description optional default

id

Isochrone identifier

yes

location

Start (or arrival point, if the reverse parameter is set to True). The coordinates are separated by , characters.

no

srs

projection (EPSG code such as epsg:4326 or wgs84)

yes

epsg:4326

exclusions

List of restriction rules to use, separated by the ; character
Available exclusion rules:
- Toll
- Infrastructure (Tunnel, Bridge)
- Hazardous material (Flammable, Dangerous, Pollutant, Toxic)
- ZFE (Zone � faible �mission, France-only) - …
- Detailled list available on the FAQ bellow.

yes

method

"time" for isochrone or "distance" for isodistance

no

time

time

Maximum access time, in seconds

yes

distance

Maximum access distance, in meters

yes

reverse

if true, the location is considered as an arrival point

yes

false

smoothing

Smoothing

yes

false

resolution

Resolution (int) of the resulting isochrone, in meters. Do not set this parameter to stay in automatic resolution mode

yes

auto

holes

Display holes in the result zone (the geometry returned is more voluminous when this parameter is set to true)

yes

false

startDateTime

Start date and time (format ISO8601: local time) Example: 2014-01-21T09:00:00.000+01:00 (or 2014-01-21T09:00:00.000%2B01:00) for a departure on 21 Januray 2014, at 9.00am in Paris

yes

snapMethod

Method for snapping to the graph
- standard: at the nearest connectable road section
- extended: via restricted road sections (pedestrian walkways….)
- nearest: only to the nearest road section
- unrestricted: without any restriction rules

yes

standard

avoidArea

Forbidden transit zone in WKT format (POLYGON or MULTIPOLYGON) in the requested projection (srs parameter)
Example in wgs84: POLYGON ((-1.556892 47.21689, -1.556892 47.216904, [...] -1.556892 47.21689)) - MULTIPOLYGON (((-1.556892 47.21689, -1.556892 47.216904, [...] -1.556892 47.21689)), ((-1.558639 47.218144, -1.558639 47.218193, [...] -1.558639 47.218144)))
NOTE: WKT geometries must be closed.

yes

configName

Name of the configuration to use:
- bicycle (not available for Japan)
- bus
- car
- delivery light vehicle
- delivery truck vehicle
- emergency truck
- emergency vehicle
- pedestrian (not available for Japan)
- taxi
- truck

yes

computeOptions

Selection of variables to use in calculations, using semi-colons ; as separators:
- speedPattern: utilization as a speed pattern. Use: "speedPattern:slow-speed"
- length: maximum authorised length in centimeters. Use: "length:950"
- width: maximum authorised width in centimeters. Use: "width:255"
- height: maximum authorised height in centimeters. Use: "height:360"
- weight: maximum authorised weight in kilograms. Use: "weight:18000"
- axles: maximum authorised number of axels. Use: "axles:2"
- weightPerAxle: maximum authorised weight per axel in kilograms. Use: "weightPerAxle:9000"
- fuelType: fuel type used to calculate carbon footprint for the journey. Available values are: "UndefinedFuelType", "NoFuel", "Diesel", "UnleadedFuel", "LGP", "CustomFuelType" and "Electrical". Use: "fuelType:Diesel"
- averageConsumption: average consumption in litres for 100 kilometers or Wh per kilometers if electrical vehicle. Use: "averageConsumption:6.45"
- cityAverageConsumption: average consumption value in city mode, in litres per 100 kilometers, or Wh per kilometers if electrical vehicle. Use: "cityAverageConsumption:4.65"
- combinedAverageConsumption: average consumption value in combined mode, in litres per 100 kilometers, or Wh per kilometers if electrical vehicle. Use: "combinedAverageConsumption:5.12"
- highwayAverageConsumption: average consumption value in highway mode, in value in litres per 100 kilometers, or Wh per kilometers if electrical vehicle. Use: "highwayAverageConsumption:5.64" - customAverageCO2UnitEmission: defines the carbon footprint in kilograms per litre. Use: "customAverageCO2UnitEmission:2.724"
- snapSpeed: snap-to-graph speed in kilometers per hour. Use: "snapSpeed:10"

yes

Output

Isochrone (isochroneResult)

parameter type min/max description

id

string

0/1

Isochrone identifier

location

string

0/1

Start (or Finish if the reverse is set to true).

srs

string

0/1

projection

time

string

0/1

Maximum access time, in seconds

distance

string

0/1

Maximum access distance, in meters

wktGeometry

string

0/1

Geometry of the isochrone, in wkt format

Possible returns

Case of an isochrone/isodistance that has been found (status is OK) 

{
  "message": null,
  "status": "OK",
  "id": null,
  "location": "2.321134,48.796575",
  "srs": "epsg:4326",
  "time": "60",
  "distance": null,
  "wktGeometry": "POLYGON ((2.32113 48.795216, 2.32113 48.795996, 2.319976 48.795996, 2.319976 48.795606, 2.3194 48.795606, 2.3194 48.795216, 2.318823 48.795216, 2.318823 48.794826, 2.318246 48.794826, 2.318246 48.795606, 2.317092 48.795606, 2.317092 48.795996, 2.318246 48.795996, 2.318246 48.796386, 2.320553 48.796386, 2.320553 48.796776, 2.3194 48.796776, 2.3194 48.797166, 2.319976 48.797166, 2.319976 48.797556, 2.320553 48.797556, 2.320553 48.797166, 2.32113 48.797166, 2.32113 48.796386, 2.321707 48.796386, 2.321707 48.797556, 2.322284 48.797556, 2.322284 48.797946, 2.322861 48.797946, 2.322861 48.797166, 2.323438 48.797166, 2.323438 48.796776, 2.322284 48.796776, 2.322284 48.796386, 2.324015 48.796386, 2.324015 48.795606, 2.323438 48.795606, 2.323438 48.795996, 2.322284 48.795996, 2.322284 48.795606, 2.321707 48.795606, 2.321707 48.794436, 2.32113 48.794436, 2.32113 48.795216))"
}

Case whereby method = distance and distance is not supplied (status is ERROR) 

{
  message: "distance parameter must not be null or 0 !",
  status: "ERROR"
}

Case whereby method + time are not supplied (status is ERROR) 

{
  "message": "time parameter must not be null or 0 !",
  "status": "ERROR"
}

Case whereby the location tag is missing (status is ERROR) 

{
message: "Location must be not null",
status: "ERROR"
}

Case whereby the start point is supplied with errors (status is ERROR) 

{{
  "message": "Location point must have 2 components separated with a ,",
  "status": "ERROR"
}

Case of a snap-to-graph error (status is ERROR) 

An error occurred : (500) error
ServiceException: Error in isochron computation|Error in smartrouting|Failed to execute calculateConcentricReachableAreas|com.geoconcept.smartrouting.SmartRoutingNativeException: failed to connect isochrone orign { -42.321134, 48.796575, 0.000000 }|failed to connect isochrone orign { -42.321134, 48.796575, 0.000000 }

FAQ

1. Is it possible to give priority to either journey time or distance?
2. How do you perform an isochrone/isodistance calculation without any tolls?
3. What are the maximum values allowed by predefined configName?
4. What are the exclusions available?
5. What are the Hazardous material exclusions?
6. What are Speed Patterns? How are they used?
7. How do you use heavy goods vehicle attributes?

1.

Is it possible to give priority to either journey time or distance?

Yes, by changing the method to "time" method for isochrone, or "distance" for isodistance

2.

How do you perform an isochrone/isodistance calculation without any tolls?

Place the exclusion Toll in exclusions.

3.

What are the maximum values allowed by predefined configName?

See list below:

configName axles weightPerAxle weight height length width

bicycle

bus

2

9500

19000

350

1350

250

car

delivery light vehicle

2

1700

3400

300

680

220

delivery truck vehicle

2

9500

19000

350

1350

250

emergency truck vehicle

2

9000

18000

360

920

255

emergency vehicle

pedestrian

taxi

truck

4

19000

39000

387

1850

255

4.

What are the exclusions available?

See list below:

Exclusion Description

Toll

if added on exclusions toll road sections are not used.

BoatFerry

if added on exclusions ferry itineraries (shipping) over water are not used.

RailFerry

if added on exclusions ferry (or train) itineraries (over water and land respectively) are not used.

Tunnel

if added on exclusions tunnels are not used.

Bridge

if added on exclusions bridges are not used.

Frontage

if added on exclusions Frontage roads (local roads running parallel to a higher-speed, limited-access road) are not used.

Paved

if added on exclusions tarmac road sections are not used.

Private

if added on exclusions road sections for which maintenance is provided by a private organization are not used.

Pedestrians

if added on exclusions road sections unauthorised for pedestrian use are not used. The configName parameter with a value of pedestrian uses this exclusion.

Automobiles

if added on exclusions road sections with restricted automobile access are not used. The configName parameter with a value of car uses this exclusion.

Trucks

if added on exclusions road sections with restricted access for lorries are not used. The configName with a value of truck or delivery truck vehicle or emergency truck uses this exclusion.

Bus

if added on exclusions road sections with restricted access for buses are not used. The configName with a value of bus uses this exclusion.

Deliveries

if added on exclusions road sections with restricted access for deliveries are not used. The configName with a value of delivery light vehicle or delivery truck vehicle uses this exclusion.

Taxis

if added on exclusions road sections with restricted access for taxis are not used. The configName with a value of taxi uses this exclusion.

Emergencies

if added on exclusions road sections with restricted access for emergencies are not used. The configName with a value of emergency truck or emergency vehicle uses this exclusion.

Carpools

if added on exclusions road sections with restricted access for carpools are not used.

Throughtraffic

if added on exclusions road sections with restricted access for non-local traffic are not used.

ZFE

if added on exclusions low carbon emmission areas in France will be excluded

(Hazardous material)

See description bellow.

5.

What are the Hazardous material exclusions?

Hazardous material defines a restriction to a road for any vehicle carrying the specific hazardous material. Hazardous material restrictions are government regulations and can be different per country.

  • Flammable: explosives, flammable, gas, combustible, …
  • Pollutant: goods harmful for water
  • Toxic: organic, poison, radioactive, corrosive, …
  • Dangerous: tunnel categories and others restrictions

6.

What are Speed Patterns? How are they used?

With the aim of suggesting journey times that take traffic conditions into account as accurately as possible, cars and trucks have 5 speed profiles (Speed Patterns) so various levels of road congestion can be taken into account over the timespan of a whole day:

  • standard normal-speed corresponds to the speed at a time when the traffic congestion is moderate (11h)
  • night fast-speed corresponds to very fluid traffic conditions, most often found at night time (3h)
  • busy slow-speed corresponds to the times when traffic congestion is at its densest (8h)
  • peak travel time very-slow-speed corresponds to times when traffic is densest in urban areas, and is slower than the category given above (8h)
  • default default corresponds to average speeds over a whole day

To use these, you will need to pass to parameter, when calling the web service, the following parameter computeOptions with the option speedPattern and specify the value of the Speed Pattern requested, always remembering to include a vehicle configName.
Example:

&computeOptions=speedPattern:fast-speed&configName=car

7.

How do you use heavy goods vehicle attributes?

You need to calculate an itinerary using either a vehicle configName using the restrictions, or by overwriting the call to the web service using the parameter computeOptions with the options length, width, height, weight, axles and/or weightPerAxle.
Example for a journey with a vehicle with a height of 4.5m:

&computeOptions=height:450