SAN DIEGO – Jack in the Box receives 70% of its traffic through the drive-thru, but guests at the bottom 25% of its restaurants have been waiting a minute longer for their orders. The same stores experienced 2% lower yearly sales than the top 25% of Jack in the Box stores.

To help solve the problem, the fast-food chain is revitalizing its drive-thrus with a $30 million to $45 million investment, according to Restaurant Business. In 2019, improvements will include digital menu boards, board canopies and landscaping. There also will be an effort to reduce complexity by simplifying operating procedures, upgrading equipment and reducing redundant items.

“With the lion’s share of the business going through the drive-thru, that’s the most prudent place to invest,” CEO Lenny Comma said on a company earnings call. “And as we evaluate how the consumer’s behavior is changing, particularly around delivery and app-related purchases, we want to make sure whatever investments we make in the future are actually fulfilling that consumer need.”

Jack in the Box owns 146 of the chain’s 2,200 locations. Franchisee owners can make improvements to their drive-thrus as well, while the 600 oldest franchisees have the option to remodel.

The company already offers delivery; More than 75% of its system is served by one or more delivery companies such as Grubhub and Postmates. Future plans also include a mobile app, which the company will roll out later this year.

While drive-thrus account for a majority of fast-food sales, the decision to invest in them depends on a chain’s market strategy. Earlier this month, Taco Bell announced that its new locations in large urban areas would have no drive-thrus. The “urban inline” stores are designed for walkable neighborhoods where traditional stores would be a poor fit.