Walmart has a big change rolling out to customers throughout the year.

In a letter to shareholders, Walmart president and CEO Doug McMillon recently announced plans to continue the expansion of delivery.

“We’re moving with speed,” McMillon wrote. “By the end of the year, in the U.S., we’ll deliver to 95 percent of the population in under three hours.”

The changes are backed by automation in the supply chain for stores and Walmart’s website.

Part of that automation includes a recent change in how Walmart maps out its delivery routes. The nation’s largest retailer announced it was switching to “geospatial technology” to optimize delivery zones. In the past, Walmart delivery was based on traditional boundaries like ZIP codes. Now, large areas will be divided into smaller, more precise hexagonal grids that resemble pixels in a digital image. The hexagons are linked together to cover a greater area and prevents small areas around the edges from being left out of the delivery zones.

The change gives Walmart the ability to adjust delivery zones with greater accuracy and makes it easier for items from one store to be delivered to another.

The new mapping expands Walmart’s delivery to an additional 12 million people.