Estimated wait times will now be included in Google Search and Maps to help people figure out when they should visit a restaurant. The estimates are generated using anonymized data from mobile users who have Location History enabled on their device.
That data enables Google to tell users when a particular restaurant is likely full or relatively open. If you're not booking ahead of time, being able to browse local restaurants and see which ones are most busy is helpful.
This feature builds upon Popular Times, which uses historical data from mobile devices to figure out when businesses are busiest and quietest. Like with other businesses, you can browse estimated wait times on various days.