Fields "travel speed" and "travel time"

Characteristic

Detailed Consideration

Network vs. speed class

The map data comprises a network class A network class is an indicator of importance within the road segment sectioning. The road segments are divided into eight network classes by importance of the roads they represent. The network class 0 represents the most important roads, for example highways, while road segments of network class 7 are the least important roads, for example pedestrian paths. The term network level is often used synonymously, in fact the network level equals the network class plus one. and a speed class for each segment. The network class indicates the importance of a network segment. There are eight network class levels (e.g. 0 for highways and 7 for pedestrian paths). The speed class depends on the network class and additional information such as speed restrictions or maximum speeds on different roads (highway, trunk road, rural road, city road). Roads of the same network type may have different maximum speeds, e.g. for wide or narrow, steep or even roads, mostly empty or congested roads, roads with or without many traffic lights, and so on. The actual mapping from network- and speed class to the speed used for the calculation of the travel speed is performed dependent on the vehicle The term vehicle describes what is being routed or planned for. Vehicles are used in route calculation, distance matrix calculation and effectively also in tour planning. In route calculation, vehicle properties like overall size, weight and speed are in focus. In tour planning, it is vehicle properties like capacity and availability. Commonly a vehicle is motorized, like a truck - including its trailer or a car. However also a bike or even a pedestrian are included in this definition. type.

Speed profile parameters

Users may influence this mapping through the type Speeds in the vehicle profile. It contains parameters that are used together with the network class and speed class of the network segment to define the actual speed. Minimum and maximum speeds are provided in speedRangesByNetworkClass for each network class.

{
				"speeds": {
				"speedRangesByNetworkClass" : {
				"maximumSpeeds" : [80, 65, 55, 45, 40, 30, 30, 30],
				"minimumSpeeds" : [55, 30, 23, 20, 18, 15, 15, 15]
				},
				"maximumSpeed": 75
		}

Those speed intervals are mapped to the speed classes, as shown in the diagram below. The mapping is performed by a linear interpolation. In addition to the speedRangesByNetworkClass the speed node also contains a maximumSpeed which defines the absolute maximum speed in [km/h] for all road segments.

The graph below describes the relationship between speed class, actual speed and the configured maximum speed for a single network class.

N_min  and N_max  correspond to the minimum and maximum speed configured for the network class. While these speeds are usually reached at the lowest or respectively highest speed class they both are limited by the configured maximum speed. In the graph above this results in N_max for the network class not being reached even on the highest speed class.

Good to know

Related Topics