(Inside Science TV) -- The city where you live could affect your health.
Wesley Marshall, a civil engineer at the University of Colorado, Denver, found that older cities are actually safer for their residents than many newer ones.
"The older cities were killing three-times fewer people than the newer cities," said Marshall.
Researchers say that crashes on major roads that tend to support cul-de-sac style designs are more likely to be fatal because the roads are wider and cars tend to go faster on wider roads.
He says that many older cities have a more compact grid pattern -- as opposed to the newer tree pattern. Cars on the older grid system can't travel as fast, so there are fewer traffic fatalities.
"The idea is when you have a more compact street network and your intersections are fairly close together, then what happens is the traffic speeds can’t really get up to a high speed," Marshall explained.
A recent study also found these older, compact cities had healthier residents. The study suggests that the more intersections a city contains, the lower the rates of obesity, diabetes, high blood pressure and heart disease among its citizens.
"These older, more traditional neighborhoods were facilitating more walking, biking," said Marshall.
Neighborhoods with large retail stores had a 14 percent higher rate of obesity and a 25 percent higher diabetes rate. The elevated risk could be because the areas aren't very walkable and driving is an easier means of transportation.
"I was definitely surprised at the order of magnitude we saw in the differences in something like obesity and diabetes," said Marshall.
The healthiest cities had shorter blocks and more intersections, while the less healthy cities had wider lanes and more major streets.