The traffic accidents on the highway No.1 in front of the University of Phayao take place often inasmuch this university has officially been established since 2010. Since the highway No.1 is the arterial providing for the movement across the city and moreover the communities in front of the university have been expanding rapidly, as a result, the volume of traffic increases accordingly. These inevitably lead to the high rate of accidents by traffic flow conflict especially at U-turns. This paper presents a possible 3-leg signalized intersection by using the criteria of the highway department (e.g., traffic volume, a number of accidents, a number of pedestrians crossing, road network) in such a way that the problem of traffic accident would be reduced.