Motor coaches are the fastest growing form of long-distance transport in the United States, and British-owned companies are leading the charge. So has the US finally learned to love the bus?

"Imagine if William Shatner had crashed a plane into the side of a building. The airline industry would go crazy."

Dan Ronan, chief spokesman for the American Bus Association, has a bone to pick with Captain Kirk.

The object of his irritation is an advertisement for travel website Priceline, currently on heavy rotation on American television, which features William Shatner on board a bus that plunges over a precipice and explodes in a spectacular fireball.

The ABA feels the ad is in "poor taste" but what really irks the industry is that Shatner's bus is not a modern, air-conditioned vehicle with leather seats and wi-fi but a beaten-up museum piece from the 1950s.

The British invasion Much of America's bus industry is now owned by two Scottish companies

Stagecoach owns intercity, local, commuter, city sightseeing, tourist and yellow school buses through its Coach USA subsidiary

It launched Megabus in the US in 2006, expanding rapidly to serve 72 major cities from hubs in Chicago and New York

FirstGroup took over US firm Laidlaw in 2007 for $2.8bn (£1.78bn), giving it control of the 92-year-old Greyhound bus line

It launched BoltBus in 2008, initially going head-to-head with Megabus on the key New York to Washington route

Inter-city bus travel grew by 7.1% in 2011, compared with 1.5% for air and 1.16% for rail, according to DePaul University

It seems to sum up the average American traveller's view of buses as the transport option of last resort - slow, uncomfortable and out-of-date.

According to ABA president Peter Pantuso, the last time most Americans took to the road in public transport was in the yellow bus that took them to school.

Persuading them to take their first trip on a modern coach is the toughest task he faces.

Not so 70 years ago. The heyday of long-distance coach travel in the US was during World War II, when seats on Greyhound buses were filled to capacity with troops and civilians.

The industry tried to capitalise on its new-found popularity with high-profile marketing campaigns but the rapid growth in cheap air travel and car ownership during the 1950s sent it into steep decline and it was steadily relegated to the margins.

It is unlikely to ever recapture its wartime glory years - the US is simply too big to make coaches practical for most travellers.

But rising petrol prices and a new breed of British-owned discount operators, based in the densely populated north-east corridor, have made the coach a viable alternative to the car, plane or train for a growing number of travellers.

According to the authors of a report by DePaul University's Chaddick Institute for Metropolitan Development, Megabus and BoltBus could even make bus travel "cool".

Public transport passenger trips New York - 3.2 bn

- 3.2 bn Chicago - 0.52 bn

0.52 bn Los Angeles - 0.48 bn

- 0.48 bn Washington DC - 0.44 bn

- 0.44 bn Boston - 0.37 bn

- 0.37 bn Source: 2009 Public Transportation Fact Book

The two British-owned companies, which went head-to-head on key US routes for the first time in 2008, increased their number of trips by 32% last year and are adding new routes all the time.

The key to their success is offering tickets between major cities such as New York and Philadelphia, or Boston and Washington, for as little as $1 (63p), with typical one-way fares between $15 (£9.53) and $27 (£17.07).

But the fact that they offer free wi-fi and pick up passengers on the kerbside - rather than bus terminals which are seen as dirty and intimidating - is also a factor, helping to make them popular with more affluent passengers and women travelling alone, according to the DePaul research.

The companies also stress the green credentials of buses, which offer better carbon dioxide emissions than air or car travel.

American operators such as DC2NY are also getting in on the act, but while passengers travelling between Washington DC and New York pay a lot less than rail or air travellers, the journey is at least an hour slower than the slowest train.

Inter-city kerbside bus departures have increased from 589 to 778 a day over the past year, while scheduled departures for the industry as a whole, including Greyhound, which shares a British parent company with BoltBus, increased 7.1% to 2,693.

Buses in the US Rail dominated transport in America before 1910, when the private car began its ascendancy

Inter-city bus travel reached a peak of 27 billion passenger miles during World War II, enjoying its highest-ever market share

Coach travel rivalled rail in the 1950s and 1960s, with marketing campaigns for Greyhound buses featuring a live dog, Lady Greyhound

Greyhound was also the official transport of the Miss America contest

Buses and rail both lost market share to airlines with trains eventually being bailed out by the government

Urban transit services were taken over by the public sector in 1960s

City-to-city coaches stayed in private hands but hit financial trouble in the 1970s

Market deregulated in 1982 but strikes hamper recovery

Discount kerbside services launched in 2006

There has also been a boom in rogue operators - anyone who can scrape together $300 for a licence can start a city-to-city coach service.

The ABA is calling for a tougher inspection regime after a spate of deadly accidents last year, although it insists the industry's overall safety record is a good one.

It is also proud of the fact that it has survived without taxpayer support - unlike the rail industry or the buses that operate in America's cities.

City buses also have an image problem - best summed up by the 1994 movie Speed, which featured a model of bus from the 1950s despite being set in the present day.

Joni Hamill, an intellectual property assistant, waiting for a bus a few blocks north of the White House in Washington DC, says most of her colleagues travel to work by car and regard her choice of transport as a little strange.

"People feel like the bus is dirty," she says.

Her husband Karl says he started travelling to work by bus when he moved from Alabama but he would not consider using public transport in any other American city as the standard of service is "miserable".

Image caption American bus users are emerging from the shadows

City buses were taken into public ownership in the 1960s but although they are subsidised by the state, they have been starved of cash in recent years.

Some cities have set up dedicated busways, rebranding them as "trains with rubber wheels".

But all of the new government money has gone on rapid transit schemes, seen by politicians and planners as the only way to tempt motorists out of their cars. Federal spending on light rail increased from $494m (£314m) in 1992 to $3.7bn (£2.35bn) in 2008.

Transit ridership, and public transport in general, is growing faster than car mileage, which appears to have peaked in the US, according to American Public Transport Association figures.

But critics say some systems are virtually deserted outside of the rush hour and are not as cost-effective as buses.

The stigma about buses falls away as buses become useful Jarrett Walker, Transport consultant

Marc Scribner, a transportation analyst at Washington DC-based think tank the Competitive Enterprise Institute, says any subsidy for public transport should be spent on small local buses that are better able to serve the vast, car-friendly suburbs than what he sees as cumbersome and inflexible rail systems.

A bill due to be voted on in the House of Representatives next month could end a dedicated funding source for mass transit introduced by the Reagan administration in the early 1980s.

If it becomes law, the Republican-backed bill would eliminate the Mass Transit Account in the Highway Trust Fund, which is funded by a 2.86 cents-per-gallon (1.82p) federal tax on petrol. Currently 25% of the fund goes on transit; in future it would all go to fund highway improvements.

'High-density living'

Some officials fear this would have a devastating impact on cities with high levels of public transport such as New York, leading to increased fares, service reductions and more frequent breakdowns.

Many on the right argue that the answer is to deregulate and privatise America's city buses, setting them free to pick up passengers at the kerbside or even operate door-to-door services.

But Jarrett Walker, an international transport planning consultant and author of new book Human Transit, argues that this would not lead to a better standard of service, pointing to the "free-for-all" that followed bus deregulation in Britain in the 1980s.

He does, however, believe that the growth of public transport in America has become unstoppable, as young people turn their back on the suburbs and opt for "high-density" urban living.

The cities of the future will only be able to function with fully integrated bus and train services, as well as cycling and walking.

He believes it would not take much - clearer timetabling and more "civilised" facilities - for most Americans to overcome their objection to boarding the bus.

"The stigma about buses falls away as buses become useful," he says.