The website Walk Score said today that data it has collected across the country suggest show that Philadelphia has the fifth best public transit system in the nation.

Walk Score, a for-profit venture funded by angel investors, said it derived the rankings based on an average resident's access to public transit, which in Philly means SEPTA. It used data from 1.9 million locations across 316 cities and plugged the numbers into a proprietary algorithm. The top 10 cities list includes cities with populations of more than 500,000 people.

It scored cities on a scale of 0 to 100. The top five:

-New York, 81

-San Francisco,80

-Boston, 75

-Washington D.C., 70

-Philadelphia, 67

Walk Score, which promotes walkable neighborhoods and makes its money through housing rental ads, also ranks Philadelphia as the fourth most walkable city. It further ranks Philly as the fourth most bike friendly city.