I lost my cat Mulder for about a day 3 years ago when he got startled by my stepdad leaving and bolted. We had no idea where he was and I was literally hysterical. My DH had to pick me up from the floor of the humane society where we went looking and carry me to the car. When we found him he was hiding in the bushes of a neighbors house, too scared to come when we called.
If he's scared he's probably close by, they usually find a hiding spot to hunker down into and stay there until found. Mulder would not have come out on his own, he's a 12 yr old 20 pound house cat never been outside. Check bushes, hidey holes, recycling bins in the alley, anywhere he could fit and hide. And good for you putting tags on him. You took the right steps in making sure that if this did happen it would be 100% more likely to get him home again.
Best wishes my dear, keep us updated. Kitty is in my