Portland, Oregon is the most plugged-in city in the US, according to researchers at the Indiana University School of Public and Environmental Affairs.

In “Plug-in electric vehicle readiness: Rating cities in the United States,” published in Electricity Journal, the researchers ranked 36 cities, including the nation’s 25 largest, in terms of the policies they have put in place to encourage plug-in vehicle ownership.

“With gas prices dropping, consumers have less of a financial incentive to buy a PEV,” researcher Kyle Clark-Sutton said. “It is crucial for cities to create receptive policy environments for purchasing and operating an electric car. If they don’t, we won’t see the technology’s promise as a means of climate change mitigation fully realized.”

Under a scoring system devised by the research team, Portland, Washington DC, New York City, Baltimore, Los Angeles and Denver won the top six spots. All offer purchase incentives for PEVs and charging equipment, and four of the six offer time-of-use electricity rates. The top-ranking cities also score well in categories such as public charging station density, special parking privileges and high-occupancy-vehicle lane access.

“Some cities are doing more to encourage PEV ownership than others by installing new public charging infrastructure and offering various sorts of incentives,” researcher Saba Siddiki said. “PEV owners enjoy free parking in downtown Nashville and are exempt from all parking fees in Honolulu. Portland has streamlined the often complicated permitting process for home-based chargers. In Austin, PEV drivers can subscribe to unlimited use of 250 public charging stations located around the city for less than $5 per month.”

Those services and incentives are largely absent from the bottom six cities.

The full ranking:

1. Portland OR
2. Washington DC
3. Baltimore
4. New York City
5. Denver
6. Los Angeles
7. Atlanta
8. Chicago
9. Austin TX
10. San Francisco
11. Boston
12. Houston
13. Indianapolis
14. Orlando FL
15. San Diego
16. Seattle
17. San Jose CA
18. Hartford CT
19. Phoenix
20. Fort Worth TX
21. Honolulu
22. Nashville TN
23. Dallas
24. Jacksonville FL
25. Newark NJ
26. Raleigh NC
27. Burlington VT
28. Philadelphia
29. San Antonio
30. Charlotte NC
31. Memphis TN
32. Detroit
33. El Paso TX
34. Portland ME
35. Providence RI
36. Columbus OH

Source: Indiana University
Image: Parker Knight (CC BY 2.0)