Description

In some cases, you may have dedicated right turn lanes (or left turn lanes for left-side driving locales), where vehicles entering and exiting the zone are already traveling in the turn direction rather than the approach direction. An example of such a zone is shown in the image below. In this case, you may find that GRIDSMART labels many of those counts as thru movements rather than right turns.

How this happens

GRIDSMART records turning movement counts based on the direction an object travels with respect to the flow arrow of the last exited zone. This means that dual-use (e.g., thru and right) zones can be counted accurately and that u-turns from left turn zones can be counted, but also means that a vehicle that exits the intersection in the direction of the zone flow arrow will likely be counted as a thru.

Solution

Point the zone flow arrow in the approach direction, rather than in vehicle travel direction, and turn on left side entry. See this Solution for more detail.