The relationship between driver and passenger's seatbelt use: a bivariate probit analysis

Vehicle seatbelt has been shown to have a beneficial impact on occupants. However, some occupants do not use the seatbelt when inside a moving vehicle. Despite the numerous investigation on the risk factors associated with seatbelt use by occupants, little is known about the relationship between driver and passenger seatbelt use. This gap is analyzed with road side observational survey data on driver and front-right seat passenger's seatbelt use behaviour using bivariate probit model. The use of the bivariate probit model is based on the premise that the front-right passenger's seatbelt use is endogenously related to that of the driver. Out of the 5,433 vehicles observed, the prevalence rate of driver and front-right passengers' seatbelt use were 81% and 33%, respectively. In addition, there is a positive relationship between driver and passenger's seatbelt use with correlation coefficient of 0.53. Thus, the unobserved factors that influence the probability of a driver seatbelt use also influence their front-right passenger's seatbelt use propensity.