Autonomous Audi SQ5
Using radar and intelligent software, the Audi SQ5 can make human-like decisions when driving on motorways Delphi

A specially modified Audi SQ5 is driving itself 3,500 miles from San Francisco to New York City as part of an experiment into autonomous cars navigating motorways without human input.

Built by Delphi, an automotive equipment manufacturer, the car will collect a total of 2.3TB of data during the trip, which is expected to take eight days. The car will drive for no more than eight hours per day, allowing it to complete the journey entirely in daylight and within the speed limit. Its 30 March arrival in New York will coincide with the city's annual motor show.

Humans will be in the car for its entire trip, although their input will not be required while it is driving on freeways. They will need to take over to navigate the smaller and more complicated roads of towns and cities, as is the case with most self-driving vehicles.

The car uses radar and an array of sensors to understand its environment and stay in the correct lane. Intelligent software enables the car to make "human-like decisions for real-world automated driving," Delphi said.

"Delphi had great success testing its car in California and on the streets of Las Vegas," said Jeff Owens, Delphi's chief technology officer. "Now it's time to put our vehicle to the ultimate test by broadening the range of driving conditions. This drive will help us collect invaluable data in our quest to deliver the best automotive grade technologies on the market."

Self-driving cars are currently a hot topic, with US electric car company Tesla announcing an upcoming software update which will bring autonomy to some of its vehicles. The Model S P85 D already has hardware modifications over older Model S cars, and with the software update will be able to navigate motorways without human input - although it is not yet clear if such features on a commercially available car are legal.

Legality will also be an issue for the Delphi-modified Audi. While California and Nevada recently legalised the use of self-driving cars on public roads, many other states have no laws governing them. John Absmeier, director of Delphi's global automated vehicle business, said: "In the rest of the states it's not precluded, but that doesn't necessarily mean that it's legal.

"So we're taking every precaution and we've notified the states ahead of time."