U.S. highways with callboxes have included most of the major highways in California, Florida's Turnpike and Interstate 185 in Georgia. Rather than a telephone, these devices simply have four buttons to push: blue for accident or other emergency (send police/fire/medical), green for major service (mechanical breakdown, send a tow truck), black for minor service (out-of-gas or flat tire), and yellow for cancel. Roads in other places may have voice call boxes, though these are more expensive, and must either be wired long distances, or rely on spotty rural mobile phone service.