Brazil's Map of Violence 2012, Traffic Accidents, a document from Instituto Sangari, found that there has been an unpleasant consequence of the explosion in the sale of motorcycles in Brazil.
In 1970, there were a little more than 62,000 of them, a mere 2.4% of the total vehicle fleet. By the year 2000, there were 4 million motorcycles and as a percentage of the total vehicle fleet on Brazilian roads and highways they had risen to 13.6%.
Preliminary figures for 2010, put the number of motorcycles in the country at 16.5 million, meaning that one in every four vehicles nowadays is a motorcycle (25.5% of the fleet).
During the last decade, while the number of motorcycles in circulation rose over 400%, the number of automobiles also rose, doubling (up 118%).
But here is the cruel twist to this story: as the number of motorcycles and automobiles both rose between 2000 and 2010, the number of deaths in automobile accidents rose only 58%, but deaths in accidents involving motorcycles leaped more than 800%.
As the numbers rose, there was a perverse "category" shift in traffic accidents. As a rule, it is the vulnerable pedestrian who leads the statistics, followed by automobiles. Thus, in 1996, over 24,000 pedestrians died in traffic accidents and 7.188 people in automobiles. In third place, motorcyclists: 1,421.
Ten years later (in 2007, when 12,362 pedestrians died in traffic accidents), a significant turnaround: more motorcyclists died, 10,392, than people in automobiles, 10,218.
Note that between 1996 and 2007, pedestrian deaths fell by 50% and automobile deaths rose less than 50%. During the same period deaths on motorcycles were up almost tenfold.
In 2009, the great (but sad) turnaround: more motorcyclists died than pedestrians in traffic accidents in Brazil (11,839 to 11,194, with automobile deaths in third place: 10,347)
Julio Jacobo Waiselfisz, a sociologist who wrote the Sangari report on highway violence, says the tendency is for the number of motorcyclists dying in traffic accidents to rise even more as the number of them on the road will continue to increase. He points to easy credit for installment buying, people with more money and the transportation necessities of modern life.
"Motorbikes have become a necessity for many and in general they solve the problem," says the sociologist. But, he adds, before they became easy to acquire, they were a middle class consumer's dream. "You know, there was this thing about being free and feeling the wind in your face."
According to Jacobo, traffic regulations and enforcement pay a lot more attention to vehicles with four wheels than two. "Many speed traps in Brazil (radar) cannot capture clear images of motorbike license plates. They need a different type of equipment."
Jacobo has some chilling numbers to describe the situation. He points out that during the last decade, while the number of automobiles on Brazilian roads doubled, the chances of dying in a car accident was actually falling.
That is the opposite of what is happening with motorcycles. Statistically, says Jacobo, a motorbike rider's chances of dying in a road accident nowadays is 14 times that of someone in a car.
Every week the emergency room at the Hospital das Clínicas in the University of São Paulo School of Medicine receives an average of eleven victims of motorcycle accidents.
A worrisome statistic is that 35% of people riding motorbikes who die in traffic accidents are found to have been involved in substance abuse or were drinking in excess.
Dr Julia Greve, an orthopedist at the hospital, points out that while there has been a general reduction in traffic accidents in São Paulo, down 35% between 2008 and 2012, the number of accidents with motorbikes rose 14% during the same period.
The victims of motorbike accidents now occupy around 60% of the beds in the hospital and Dr Greve says the institution is near the point of saturation. She goes on to say that the situation in São Paulo is critical because of cultural and behavioral factors that have made the city into a transportation beehive: with 11 million inhabitants, there are over 7 million vehicles.
According to Dr Greve, the only solution is to change behavior, invest heavily in public transportation and create restrictions on the individual use of cars and motorbikes. She also insists on more rigorous punishment of drunken driving.
The traffic problem in São Paulo is so serious that the city held an international seminar on the subject last month with the participation of renowned experts from around the world: Gjerde Hallvard, from the Norwegian Institute of Public Health, Eugênia Maria Rodrigues, from the Pan-American Health Organization (Opas) and Chip Walls, from the Criminal Toxicology Laboratory at the University of Miami.