There is a concern of incorrect reporting of seatbelt usage by occupants in motor vehicle crash reports. There is no agreed standard statistical method to adjust for the incorrect information when computing the seatbelt usage rate. Currently, the seatbelt usage rate is computed as if there is no incorrect reporting of seatbelt usage. Therefore, the obtained estimator overestimates the true seatbelt usage. In this presentation the Bayesian seatbelt usage estimate is introduced by using national seatbelt usage rates as the prior information. It is reasonable to assume the number of belted occupants, X, has a binomial distribution with n total numbers of MVC and seatbelt usage rate p. Let p_N be the national seatbelt usage rate and p_obs (=X/n) be the observed proportion of belted occupants. It can be shown mathematically that the seatbelt usage rate given p_N can be estimated as follow. To evaluate the properties of the above estimate, the simulation study was conducted. The absolute difference between the true value and estimated seatbelt usage rate was used to measure the quality of the estimate. The incorrect information on the observed belted occupants was assumed at 1%, 1.5%, and 2%. The true proportions of belted occupants and national seatbelt usage rates were examined from 0.5 to 0.9. The result showed the Bayesian estimate outperforms the usual estimate almost in all situations when the proportion of incorrect information is large (1.5% and 2%). Therefore the Bayesian estimate is warranted if the incorrect reporting is somewhat greater than 1%.