An
automated highway system (AHS), or
smart road, is a proposed
intelligent transportation system technology designed to provide for
driverless cars on specific right-of ways. It is most often recommended as a means of
traffic congestion relief, on the grounds that it would drastically reduce following distances and headway, thus allowing a given stretch of road to carry more cars.
Principle In one scheme, the roadway has magnetized stainless-steel spikes driven one meter apart in its center. The car senses the spikes to measure its speed and locate the center of the
lane. Furthermore, the spikes can have either magnetic north or magnetic south facing up. The roadway thus provides small amounts of digital data describing interchanges and recommended speeds. The cars have
power steering and automatic speed controls, which are controlled by a computer. The cars organize themselves into platoons of 8 to 25 cars. The cars within a platoon drive themselves a meter apart, so that air resistance is minimized. The distance between platoons is the conventional
braking distance. If anything goes wrong, the maximum number of harmed cars should be one platoon. An overview of platooning systems is given in Bergenhem
et al. Platooning of trucks has been proposed as a concept to reduce the energy consumption of semi-trucks and improve the feasibility of electric semi-trucks.
Early development The origin of research on AHS was done by a team from
Ohio State University led by Robert E. Fenton, based on funding from the U.S. Federal Highway Administration. Their first automated vehicle was built in 1962, and is believed to be the first land vehicle to contain a computer. Steering, braking and speed were controlled through the onboard electronics, which filled the trunk, back seat and most of the front of the passenger side of the car. Research continued at OSU until federal funding was cut in the early 1980s.
Deployments United States The USDOT-sponsored National Automated Highway System Consortium (NAHSC) project, a prototype automated highway system, was tested in
San Diego County, California in 1997 along
Interstate 15. However, despite the technical success of the program, investment has moved more toward autonomous intelligent vehicles rather than building specialized infrastructure. The AHS system places sensory technology in cars that can read passive road markings, and use radar and inter-car communications to make the cars organize themselves without the intervention of drivers. Such an
autonomous cruise control system is being developed by
Mercedes-Benz,
BMW,
Volkswagen and
Toyota. The Federal Highway Administration in 2013 funded two research projects in heavy truck platooning (without steering automation). One is led by Auburn University with
Peterbilt,
American Trucking Associations,
Meritor Wabco, and
Peloton Technology and the other is led by California Department of Transportation, with UC Berkeley and Volvo Trucks.
SARTRE The SARTRE Project (
Safe Road Trains for the Environment), is a European Commission funded project investigating implementation of platooning on unmodified European motorways. The project begun in September 2009, and vehicle platooning, as envisaged by the SARTRE project, is a convoy of vehicles in which a professional driver in a lead vehicle heads a line of closely following vehicles. Each following vehicle autonomously measures the distance, speed and direction and adjusts to the vehicle in front. Once in the platoon, drivers can do other things while the platoon proceeds towards its long-haul destination. All vehicles are detached and can leave the procession at any time. ;EU Truck Platooning Challenge During its Presidency of the European Union in 2016, the Netherlands organised a European Truck Platooning Challenge. Six brands of automated trucks –
DAF Trucks,
Daimler Trucks,
Iveco,
MAN Truck & Bus,
Scania AB and
Volvo Trucks – ran on public roads from several European cities to the Netherlands.
Japan In January 2018, trucks from different manufacturers were successfully driven by platooning for the first time on the
Shin-Tomei Expressway in Japan.
South Korea In November 2019, Hyundai Motor Group successfully conducted its first platooning of trucks on a highway for the first time in Korea. Demonstrations of platooning, cut-in/cut-out of other vehicles, simultaneous emergency braking, and V2V communication technology were conducted. ==Innovation==