| Business | Phone |
| Aeronautics Administration 800 S Bay Rd, Dover 19901 | (302) 760-2149 |
| Highway Division 800 S Bay Rd, Dover 19901 | (302) 760-2201 |
| Highway Safety Office 303 Transportation Cir, Dover 19901 | (302) 744-2740 |
| Public Safety Dept 303 Transportation Cir, Dover 19901 | (302) 744-2680 |
| Transportation Dept 800 S Bay Rd, Dover 19901 | (302) 760-2080 |