The Robins, who will start the new campaign with a tough trip to Preston, drew 13 of their 23 home games last time out, and Johnson knows that is where they need to improve.
"It is a little disappointing to find out we're away on the opening day, Boxing Day and the final day of the season for the second season running," he told his club's official website.
"Our away from last season was okay, so I suppose it isn't too bad in that case. We just need to improve our home form, turning those draws into wins.
"We've got long journeys to start and end the season, so we've got to make sure we give our supporters - who will travel in big numbers - something to cheer about."