I want to advertise the road gate, but an advertising company in the same city says it has a patent. What else can I do?

yes, as long as your product does not cover all the technical features in the independent claim of the patent, it will be fine.

For example, the independent claim of this patent is:

An advertising information display device, which is characterized by comprising a base body, a light box fixing body and a light box, wherein one end of the base body is fixedly connected with the light box fixing body, a convex button is arranged at the joint of the base body and the light box fixing body, and a concave button matched with the convex button is arranged on the inner diameter of the opposite light box fixing body; The matrix is a hollow cuboid made of a hard plastic plate, the light box fixing body is a hollow cuboid made of a light plastic plate, and a light source is arranged in the light box; The surface of the light box is provided with an information dissemination surface for advertising and display.

The products you make can be made into solid cylinders without convex buttons, and the light source can be placed outside the light box and so on. . . In short, as long as it is different from the technical features in the independent claim above, it will not infringe (change as much as possible to prevent equivalent infringement).