Today's post is a continues our series on calibrating SimTraffic. Along with the Lane Alignment and Positioning Distances, the Link OD Volumes determine lane utilization in SimTraffic.
Located in the Volume Settings window, the Link OD Volumes window allows control over the origin and destination of two adjacent intersections. Link OD Volumes can be used to reduce or eliminate certain turn combinations, such as preventing vehicles from turning left twice at a freeway or wide median arterial.
The 2010 Highway Capacity Manual (HCM) procedures may be used to analyze coordinated intersections, but there are some unique settings such as the Platoon Ratio required for accurate results. Chapter 18 in HCM 2010 highlights the procedures related to isolated signalized intersections, while Chapter 17 focuses on the procedures associated with coordinated intersections. The Platoon Ratio describes the quality of progression for a platoon of vehicles arriving on green. As described in HCM 2010, the user should select a Platoon Ratio based on field observations and their knowledge of the corridor.
Table 1: Traffic Flow Along Coordinated Arterials