Staying in or near the pod wasn't really on Rick's mind. It was just a touch too claustrophobic for him, so he just had to get as far away from it as he could. Plus, his priorities right then were finding his people, and specifically, his son and Michonne. If that meant he had a one-track mind, then he'd just accept that, because it was true.

What he didn't bargain for was the presence of walkers, but he was a pretty fast runner, and as he made his way along, he noticed walls looming up ahead of him. He frowned, because from out here, he couldn't tell what might be waiting for him inside those walls. He didn't want to walk blindly into another Woodbury or Terminus.

So with those sobering thoughts in mind, he slowed his pace some, hoping to find a vantage point to see what was going on inside. To say he didn't trust it just because it was walled was understating the facts.