NHVR Truck Routing in Australia

1. What is NHVR?

The National Heavy Vehicle Regulator (NHVR) administers the Heavy Vehicle National Law across participating Australian states and territories. It defines designated road networks for heavy vehicles, such as B-doubles and road trains, identifying authorized routes and their access conditions.

NextBillion.ai integrates NHVR network data into its routing platform, enabling logistics operators and fleet-management applications to generate routes that prioritize designated heavy-vehicle networks for supported truck categories.

2. How does NextBillion.ai implement NHVR-based routing for regulated vehicles?

NextBillion.ai's Flexible Routing APIs integrate designated NHVR heavy-vehicle road networks with the regular road map network. The routing engine uses vehicle-specific network classifications to calculate routes that prioritize roads designated for the selected truck type.

Users can configure NHVR-aware routing, using Directions Flexible API as example, through the following parameters:

NHVR network membership is evaluated separately from physical road restrictions. The API also supports truck-specific constraints such as vehicle height, width, length, weight, axle load and hazardous-material restrictions through dedicated request parameters.

3. Is NHVR compliance a hard rule or a preference? Can the routing engine leave the designated network?

NextBillion.ai supports both preferred-network routing and strict network-only routing, depending on the configuration.

Preferred-network routing

When prefer=truck_route is enabled, the routing engine applies an additional routing cost to road segments outside the designated network for the selected truck_type. Consequently, the engine generally favors NHVR-designated roads but may select an off-network segment if the overall route cost remains lower, even after the penalty. This commonly occurs during first-mile and last-mile routing, where pickup or delivery locations may not be directly connected to a designated heavy-vehicle network.

Strict network-only routing

To enforce designated-network membership as a hard routing constraint, use require=truck_route. It restricts the calculated route to use designated truck-network roads only. However, to better facilitate the first-mile and last-mile routing, where pickup or delivery locations may not be directly connected to a designated heavy-vehicle network, the restrictions are slightly relaxed such that the routing engine doesn’t fail a request if it can find a designated network road within 2 km radius of the origin, destination or any waypoints. Only if no designated network road could be found within a 2 km radius, the API returns an HTTP 422 error.

Please note that both modes operate independently of physical road restrictions, which continue to be evaluated independently by the routing engine.

4. Which NHVR networks are mapped to each truck_type value?

NextBillion.ai currently integrates 138 NHVR road networks, categorized into five supported truck types based on the vehicle classifications identified in the source network names.

How network mapping works

NHVR publishes separate networks for different jurisdictions, vehicle configurations, mass limits and dimensions. NextBillion.ai groups the ingested networks into the five categories above to simplify routing configuration. For example, NSW's 19 m, 23 m and 25/26 m B-double networks are currently mapped to the common b_double classification. A road belonging to multiple ingested NHVR networks carries multiple truck-type classifications.

However, currently there are some mapping limitations:

• State-specific networks are combined into a unified routing dataset. The appropriate geographic network is determined by the road's location rather than by a state parameter in the request.

• Length and mass variants within a vehicle category are merged rather than exposed as distinct selectable networks.

• Direct selection of an individual NHVR network ID or WKID is not currently supported.

As a result, truck_type provides a broad vehicle-network classification rather than an exact match to every NHVR vehicle configuration, length or mass classifications.

5. Which Australian states and territories are supported for NHVR-based routing?

NextBillion.ai currently integrates 138 NHVR networks across five Australian states and territories.

Please note that:

1. Tasmania is within NHVR's regulatory jurisdiction, but its designated networks are not currently included in NextBillion.ai's NHVR integration.

2. Western Australia and the Northern Territory operate outside the Heavy Vehicle National Law framework and are not covered by the current NHVR network integration.

6. How to interpret truck_route values in the response?

When road_info=truck_route is specified, the selected service returns the designated heavy-vehicle network classifications associated with individual road segments along the calculated route.

The information is returned under routes[].road_info.truck_route, with each entry containing three attributes:

• offset: Index of the starting vertex in the decoded route geometry.

• length: Number of consecutive road segments covered by the entry.

• value: Array of truck types associated with the designated heavy-vehicle networks covering those segments.

For example:

1
{
2
  "offset": 501,
3
  "length": 5,
4
  "value": ["b_double", "generic_truck"]
5
}

This indicates that the route section from geometry vertex 501 to vertex 506 belongs to designated network roads for b_double and generic_truck vehicle types.

What does an empty value array mean?

An empty "value": [] array indicates that the road segment has no designated heavy-vehicle network classification in NextBillion.ai's integrated network dataset. It does not necessarily mean that all truck types are permitted or restricted by default.

• General Access Vehicles (GAVs), such as standard rigid trucks and semitrailers operating within applicable general-access limits, can generally use these roads unless otherwise restricted.

• Restricted Access Vehicles (RAVs), such as certain B-doubles and road trains, generally require an applicable network authorisation, notice or permit to use roads outside their designated networks.

Physical road restrictions, including height, weight, width, length and access prohibitions, are evaluated separately by the routing engine.

What does a non-empty value array mean?

A response such as "value": ["b_double"] means that the road segment is mapped to the b_double category in one or more ingested NHVR networks. It does not mean that only B-doubles are permitted on that road. Other vehicle types, including General Access Vehicles, may also be permitted to use it.

When prefer=truck_route and truck_type=b_double are configured, the routing engine prioritizes segments with this classification.

7. What NHVR restrictions and road-access data are supported by NextBillion.ai?

NextBillion.ai integrates 138 designated NHVR networks across five Australian states and territories. These networks are used alongside the underlying map's physical road restrictions to support heavy-vehicle routing.

The following table summarizes the current coverage.

How are these restrictions applied during routing?

The Routing APIs evaluates two complementary sets of constraints:

1. NHVR network-based routing: Uses prefer=truck_route, require=truck_route and truck_type to prioritize or require road segments belonging to designated networks for the selected truck category.

2. Physical road restrictions: Uses parameters such as truck_size, truck_weight, truck_axle_load, truck_axle_count and hazmat_type to evaluate vehicle-specific road restrictions independently of NHVR network membership.

This allows applications to combine designated-network preferences with the physical characteristics of the vehicle.

8. Where does NextBillion.ai source its NHVR network data?

NextBillion.ai sources designated heavy-vehicle network data directly from NHVR. The data is obtained in GeoPackage format and processed into NextBillion.ai's routing network. During this process, supported NHVR networks are mapped to the five truck categories used by the routing APIs. The resulting network classifications are then used for NHVR-specific route calculation and can be retrieved through the API's road_info=truck_route response.

9. How frequently is NextBillion.ai's NHVR network data updated?

NextBillion.ai sources NHVR network data quarterly and incorporates the updated information into its routing map releases.

All NextBillion APIs use the same underlying road-network dataset and segment-level classifications, ensuring consistency between the network information used for routing and the classifications retrieved by the APIs. Updated network data becomes available through the APIs as the corresponding map release is deployed without any additional integration or import requirements for the users.