Effect of Laterally Banked Roadways on the Rollover Threshold of Partially Filled Road Tankers

In this paper, a direct technique to estimate the rollover threshold limits of partially filled tank trucks is applied for banked roadways. Overturning and restoring moments are calculated as functions of tank shape, fill level, gradient of both liquid cargo free surface and the lateral inclination of banked road surfaces.

The static rollover threshold of tanker trucks traveling on laterally banked roadways is estimated by balancing the net value of the total overturning moment against the net value of the restoring moment. Different filling ratios are considered for circular, elliptical and modified tank vehicles. The rollover threshold limits are calculated considering a superelevation range of (0.0-0.1) for the lateral road banking as defined by Blue and Kulakowski (1991). It is shown that the vehicle rollover threshold limit increases with an increase of the angle of the lateral road banking. For example, an average increase in the limit of 23% is achieved as the lateral road banking superelevation is increased to a value of 0.1. Moreover, it is concluded that the presented rollover threshold estimation technique can be used to estimate the average design speed of a partially filled tanker truck as its travels on laterally banked curved roads.