Complex Scenario: Divided Highway

Divided highway (a.k.a. Dual carriageway) is very common in read world. It is when traffic travelling on roadways of opposite directions are separated by a central reservation. In common LRS setup, each direction is modeled as a separate route in the network. However, this often does not happen for the entirety of the route. In such case we have partially divided highway. Below is an example.

There are two data models to model partially divided highway in AgileAssets system. They are explained below.

• Gaps Mode: In this model, a separate route is built to represent each direction. The cardinal (or primary) direction route (usually East or North Bound) is continuous throughout the entirety of the route, whereas the non-cardinal (or reverse/non-primary) direction route (usually West or South Bound) has gaps when the route is undivided. This step is commonly used for agencies that do not use concurrency in the LRS. An example of this setup is shown: A01-EB is the cardinal direction route, and A01-WB is the non-cardinal direction route.

Under this model, this is what two routes look like (distance between routes is exaggerated for displaying purpose):

The LRS database tables NETWORK_GAPS, CONCURRENT_LOCATION_DOM, CONCURRENT_LOCATION_SIB, NETWORK_LINE_DIRECTIONS and SETUP_LOC_IDENT are filled as follows, to represent the above route network.

This setup will result in the following issue when recording line events when the roadways diverge or converge.

• Concurrency Model: In this model, a separate route is built to represent each direction. Both the cardinal (or primary) direction route and non-cardinal (or reverse/non-primary) direction route are continuous throughout the entirety of the route. At the portion of the roadway where it is undivided, the two routes are concurrent. A dominance rule is normally built into the network when there is concurrency. So, at the undivided portion of the roadway, the cardinal direction route is dominant, and non-cardinal direction route is subordinate.

Under this model, this is what two routes look like (distance between routes is exaggerated for displaying purpose):

The LRS database tables NETWORK_GAPS, CONCURRENT_LOCATION_DOM, CONCURRENT_LOCATION_SIB, NETWORK_LINE_DIRECTIONS and SETUP_LOC_IDENT are filled as follows, to represent the above route network.

This setup will result in the following issue when recording line events when the roadways diverge or converge.