Abstract: Improper width of right shoulder is considered as one of the most important reasons that lead to traffic accidents on highways.Meanwhile,variation of driving environments could cause disorder of driving behaviors.Therefore,with a purpose to explore the effects of different right shoulder width on consistency of driving behaviors,typical road segments with different shoulder width in Guangdong Province are chosen as samples in this study.The impacts are investigated from an aspect of vision awareness.The results indicate that when a vehicle is driving along the most right lane,the difference of the right shoulder width has the most significant influence on coordination of driving behaviors.The drivers would be distracted or feel nervous when the shoulder width is either too narrow or wide.Optimal shoulder width could help drivers to keep a safe,comfortable and effective status.In conclusion,a proper design of shoulder width of highways could reduce the risk of traffic accidents.