Buses Show Highest Safety in Traffic

Bus accidents often receive a great amount of publicity, most likely be­cause many people are riding buses and the vehicles are operated by profes­sional drivers who are supposed to be able to drive. Statistics show that only 0.3 bus passengers are killed per billion passenger kilometres. Sixteen times as many people are killed in car accidents. Statistically, one can ride 75,000 times round the world by bus without experiencing an accident.

A passenger in a bus is very safe. Accidents happen, instead, outside the bus. A detailed study for the year 1994 shows that of the 747 people killed in vehicle accidents none died in a bus. During 1994, eight people died in accidents in which buses were involved, none of the fatalities rode in the buses. The same year, 215 people were injured in bus accidents, 50 of whom were riding in buses.

For eight out of ten accidents, there was only a bus and another vehicle involved, and five of a hundred accidents were single-vehicle ac­cidents. Bus accidents can occur between passenger cars and unprotect­ed pedestrians. Often, this happens on the way to or from a bus stop, perhaps due to icy roads, and such an accident is recorded as a bus acci­dent. What is needed, therefore, is increased safety at bus stops.

The number of accidents between cars and buses fell during the 10-year period of Ingvar Holmberg's study, whereas the number of acci­dents between unprotected pedestrians and buses remained unchanged during the same period.

A Bit of Diesel History

It was 1895 when Rudolf Diesel first revealed his invention to the world: the compression-ignition engine. Compared to the already famil­iar Otto (gasoline) engine, Diesel's power plant used less (and less expen­sive) fuel, and it was suitable for much greater power outputs. It caught on; soon there was no other alternative for stationary and ship engines.

But the Diesel engine had one major drawback: it was not capable of high rotational speeds. All the same, the more its inherent advantages were recognized, the greater the interest in overcoming this hindrance to its wider use.

The main reason the Diesel engine could not be made to run fast was its fuel-feed system. Up till then, the only known method was to "blow" fuel into the cylinders using compressed air, and this was an inherently slow process. In addition, the air pump required was a large, heavy and expensive ancillary unit that precluded making the engine compact or light enough for a motor vehicle.

In late 1922, Robert Bosch decided to overcome the problem by de­veloping a fuel-injection system for Diesel engines.

Conditions were right for Bosch. He already had a great deal of ex­perience with internal-combustion engines. Production techniques were highly developed. And experience gained in the production of lubrica­tion pumps would be useful. By early 1923, Bosch had about a dozen basic designs for injection pumps. And by the middle of that same year, he was testing the first hardware on an engine.

In summer 1925, the pump design was final, and in 1927 the first production pumps left the Bosch factory.

Bosch's fuel-injection pump brought the Diesel up to speed. It was a breakthrough of major proportions, helping the compression-ignition engine master an ever-increasing variety of applications - especially in motor vehicles. Evolution of the Diesel engine now proceeded at a faster pace than ever.

Not long ago, a Diesel-powered car with Bosch fuel injection set a very fast pace indeed: a new land speed record of more than 360 km/h, or 224 mph. That's impressive enough, but its fuel consumption while setting the record - something one seldom hears about - was if anything even more impressive. At that speed, the record car consumed just 13.6 liters per 100 kilometers, or 17.3 miles per U.S. gallon. And at the "modest" speed of 250 km/h (155 mph), it got along on a mere 6 1/100 km, or 39.2 mpg!

Diesel passenger cars continue to demonstrate just how adaptable and capable of further development the Diesel engine is; despite recent local setbacks, their worldwide market share increases every year. In fact, today almost every auto manufacturer in Europe, America and Japan has a least one Diesel model either in production or under development.