Three Milwaukee suburbs among 100 safest in the nation, according to a new study

Three Wisconsin suburbs have been ranked in the top 100 safest suburbs in the nation, according to a new study — and all three are Milwaukee suburbs.

Port Washington is rated the 42nd-safest suburb in the United States. Grafton is tied for 55th, while Waukesha tied for 100th.

The survey was conducted by SmartAsset, a financial technology company based in New York City.

What are the rankings based on?

The survey determined the safety of the suburbs based on five factors:

• The suburb's rate of violent crime
• The rate of property crime
• The vehicular mortality rate, which calculates the number of traffic accident deaths
• The drug poisoning mortality rate
• The percentage of the suburb's residents who engage in excessive drinking

Port Washington, the highest-ranking of the three suburbs, had fairly consistent numbers across the board, but stood out for its low property crime rate of 709 per 100,000 residents, which was 33rd-lowest on the list.

Grafton had a very low violent crime rate of 51 per 100,000 residents, 26th-lowest of the suburbs surveyed.   

Waukesha's best ranking was in vehicular mortality rate — its rate of 5.8 per 100,000 residents tied for the 48th-lowest.

SmartAsset said the vehicular mortality, drug poisoning and excessive drinking rates were measured at the county level. The violent crime and property crime rates were measured at the city level.

How were the suburbs in the survey chosen?

SmartAsset selected 370 places that are within 15 to 45 minutes of the 100 largest U.S. cities by car and have a population of at least 5,000.