Currently, the ASEAN Community has opened and this has resulted in the expansion of the road network between member countries, making it more convenient to drive crossing the border. However, the difference in laws relating to the speed limits and their enforcement may result in drivers unknowingly violating the laws in each country, leading to an increased risk of accidents. This research aims to determine the statistical correlation between the traffic accident fatalities, the enforcement of speed limits with the gross national incomes of Thailand and its cross-border countries. Linear and non-linear regression analyses were applied to develop models explaining their correlations at 95% confidence level. The results indicated that those countries with higher efficiency in enforcement on speeding laws and greater gross national income have a lower rate of traffic accident fatalities. The results of this study are useful for responsible agencies to determine the required traffic safety strategies in order to reduce the number of traffic accidents within ASEAN countries.