A method, apparatus, system, and computer program product provide the ability to design a road intersection in a three-dimensional (3D) modeling and visualization system. Two roads are defined in the system with the second road intersecting the first road. A set of design rules (that define characteristics of use that contribute to a shape of the road intersection) is acquired. Based on the set of rules, a 3D model of the road intersection is directly created. A property of one of the roads is modified. Without additional user input, the 3D model of the road intersection is automatically and dynamically updated based on the modified property and while maintaining conformance with the set of design rules.