It was one of the less likely traffic jams, caused when three lumbering bullock carts tried to pass six others on a two-lane paved road near this bustling industrial city.

Cars, trucks and buses were forced to wait while the bullock carts -- heavily laden with families returning home from market, sacks of rice and stalks of freshly cut sugar cane -- were sorted out to resume their plodding, four-mile-per-hour pace down the road.

The bullock cart remains a mainstay of transportation in modern India, moving about 74 million tons of freight and countless millions of people around the country each year.

But engineer V. A. P. Naik said it is essentially the same vehicle used for the past 5,000 years, and the Indian Institute of Management would like to change that with its program to build a better bullock cart.

After five years of work, institute engineers have come up with three models they said can carry heavier loads with less wear and tear on the bullocks. Project coordinator Naik said the new designs are 50 percent more efficient that the traditional carts.

There is one big hitch, however. The new, improved carts cost about $100 more than the traditional design -- a veritable fortune in a country where the average per capita income is about $190 a year and farm workers are on the lowest rungs of the economic ladder.

Naik, 47, a farm-born agricultural engineer, said government has to help popularize the improved carts, even if it means subsidizing their extra costs, until farmers and city haulers realize they can make more money with them.

"Our work stops with the perfection of the design," said Naik, obviously disappointed that no government or rural-development agency has stepped forward to help spread the idea.

Prime Minister Indira Gandhi lauded the bullock cart during her speech in August to a United Nations conference on new and renewable sources of energy. She said bullock carts provide more energy than all of India's power plants, and replacing them with cars and trucks could cost as much as $40 billion.

There are an estimated 15 million bullock carts in the country, twice as many as at independence 34 years ago. Naik said they haul one-third as much freight as the nation's rail system.

N. S. Ramaswamy, director of the Indian Institute of Management and head of the project on bullock carts, placed the national investment in them at $6 billion -- the same amount put into India's gigantic rail system, which is the largest in Asia and the fourth largest in the world.

Bullock carts easily negotiate rutted tracks that pass for roads in most of India's rural areas, where two-thirds of almost 600,000 villages are not connected by roads that can take motor vehicles. Without the carts, farm families would be unable to get produce to market or to move around the countryside themselves. Ramaswamy, who has made a major study of bullock-cart use in India, estimates that farm families use bullocks (castrated bulls) 60 days a year for plowing and other farm work and 80 days a year hauling goods. But he believes villagers would use the improved carts for extra hauling that could produce some cash.

Despite paved roads, bullock carts are also used in India's major cities. About 3 million of the country's 15 million bullock carts are used in urban hauling.

In New Delhi, for instance, large containers of household goods that have traveled halfway around the world on a jet commonly finish their journey on a bullock cart. A usual sight on the street's of India's capital city at night are convoys of bullocks carts carrying 2 1/2-ton to 3-ton steel beams as long as freight cars to construction sites. The bullocks seem to know the way, for often the driver is asleep on the beam. A lantern hangs on the back as a warning to traffic.

Compared with the country's 15 million bullock carts, it has less than half a million trucks.

Naik argued that bullock carts are far more efficient than trucks, especially for hauling loads up to two tons for distances up to 10 miles, because they use no scarce and expensive gasoline.

It is, he said, appropriate technology for India, especially since the dominant Hindu religion forbids the killing of cows. India has the world's largest cattle population -- perhaps 300 million of them.

According to engineer T. Mathaian, who works with Naik, a pair of large bullocks costs about $225 while the typical farm bullock cart, which can haul loads up to two tons, costs between $335 and $445, depending on the type of wood used.

To make the improved cart, the Indian Institute of Management Engineers added roller bearings to the wooden hub so the wheels run more smoothly and placed two coil- spring shock absorbers on the yoke to ease pressure on the bullocks.

Mathaian said these additions allow bullocks to pull heavier loads faster with greater ease and, as a result of the lessened strain on them, should increase their working life.

But they do cost more, and Naik said there is no way to build a more efficient bullock cart cheaper than the traditional model.

Sample models of this cart have been tested for months by village farmers and as a result of their comments a new, improved version has been built that is ready for more extensive testing, Naik said.

Two other carts have also been designed, one to carry passengers, the other for small bullocks to pull in hilly terrain where farmers now either carry goods on their backs or use donkeys. These are still in the preliminary testing stage.

The research was financed by India's Ministry of Shipping and Transport, which sought to find ways to minimize damage the bullock carts do to roads -- estimated at about $50 a year per cart.

It is unclear whether the research will achieve that aim. But, as Naik said, "The farmer doesn't care about road damage."