Less than 20 percent of polling places were fully accessible to people with disabilities during the 2016 election, according to a new government report that urges the U.S. Department of Justice to step in.

The report released Thursday from the U.S. Government Accountability Office found that barriers were pervasive at American polling stations.

Of the 167 locations that GAO was able to completely examine both inside and out, only 29 were free of any impediments.

The remaining sites presented issues with parking, lacked an accessible entrance or path to the building or had problems in the voting area itself, the report found.

“Our work examining the accessibility of polling places for voters with disabilities during the 2000, 2008 and 2016 general elections points to the need for additional progress to help voters with disabilities enter and move through polling places, access voting systems and cast a private and independent vote,” investigators concluded in their report.

For the review, GAO looked at 178 polling places across the country that were available for early voting or on Election Day during the 2016 cycle.

Nearly all of the voting stations that GAO reviewed had accessible voting systems, but investigators found that most were assembled in a way that could impede private and independent voting.

In some cases the accessible system was not turned on or lacked earphones to allow for audio functions. Other locations did not have the accessible systems set up to accommodate those in wheelchairs or they were positioned in a manner that offered less privacy than was provided to other voters, the report found.

Under the Help America Vote Act, all polling stations are supposed to have at least one accessible voting system for federal elections. What’s more, the Americans with Disabilities Act mandates that public entities choose facilities for activities like voting that do not exclude people with disabilities.

GAO recommends in the report that the Justice Department study how existing polling place accessibility requirements are being implemented, particularly during early voting, and issue additional guidance accordingly.