The estimated cost of Honolulu's planned elevated commuter rail climbed $200 million to about $3.9 billion to account for inflation since 2006, according to a new city study.

The updated capital cost and other details surrounding the project will be released in an executive summary of the project's draft environmental impact statement scheduled for release later today.

The entire document will be released by chapter over the weekend, according to city spokeswoman Elisa Yadao.

The release of the document is being delayed for several days to allow for the inclusion of material to address Hawai'i environmental laws, the city said.

The previous $3.7 billion estimate for building the 20-mile line from East Kapolei to Ala Moana was based on 2006 costs.