Abstract-The informal transport industry in Sub-Saharan Africa is notoriously dangerous, leading to many fatalities annually. This paper presents an innovative way of monitoring driver behaviour, in real-time, by taking into account road design standards, vehicle dynamics, and passenger comfort. Two models are presented that each combines acceleration and speed data into an erratic driving detection algorithm. The first model is developed though the evaluation of empirical results taken from trips in a minibus taxi, and subjectively gauging recklessness from a passenger's perspective. The second model presents a novel use of commonly used civil engineering principles, used in road design. Evaluation of the models, using actual minibus data, demonstrates that both successfully detect reckless driving, but the second model proves to be simpler and less processor intensive.