Private entrepreneurs develop additional facilities, such as truck stops or travel centers, restaurants, gas stations, and motels in clusters on private land adjacent to major interchanges. In the US, Pilot Flying J and TravelCenters of America are two of the most common full-service chains of truck stops. Because these facilities are not directly connected to the freeway, they usually have huge signs on poles high enough to be visible by motorists in time to exit from the freeway. Sometimes, the state also posts small official signs (normally blue) indicating what types of gas stations, restaurants, and hotels are available at an upcoming exit; businesses may add their logos to these signs for a fee.