I suspect that this is a work in progress, which is why I'm not limiting it to hotels and restaurants as noted elsewhere... and I suspect it's where Google was going with Pigeon.
As reported today by Greg Sterling at Search Engine Land... Google Drops Local Carousel For Hotels, Restaurants & Other Local Listings
Google is dropping its horizontal Carousel display of local search results in several categories: restaurants, nightlife, entertainment and hotels. Itís being replaced by a 3-pack of organic listings and some new secondary pages.
The Local Carousel rolled out in June, 2013 for the PC in the US and gradually expanded to a number of categories beyond local results (e.g., US Presidents). Itís not clear whether it will remain for these non-local search results.
Since day one the Carousel has been controversial among local SEOs and even among those involved in the European antitrust negotiations with Google (it has not launched in Europe)....
From what I've been able to tell after a moderate amount of searching, the "deep" individual listings that replace the Carousel hotel and entertainment results are accessed in a variety of ways, depending on the type of result. But Local information results are now changing as well, though not (yet?) in the Carousel.
First pass only on this, and this is evolving as I'm checking it, so please forgive if it's not precise... for hotels and for movies...
...the Carousel is dropped, and clicking the "More hotels" link (beyond a few top organic results on the first page) displayed subsequent pages of hotel listings only (previously in the Carousel) that now allow sorting by price, availability, etc.
For these results, Google apparently is using room availability data, and using this data whether or not Google was offering associated bookings. I'm assuming there is either a data feed or third-party data, resembling shopping results. Ditto for movie listings (where, as before, there is an independent data set). I can only guess about the availability data.
Within, say, the sorted hotel list, clicking on any single hotel listing itself brings up a column with a Knowledge Graph panel up at the top, possibly followed by booking options, and then by review/booking sites in what appear to be some sort of organic order.
There is also a Local information aspect to these deeper results, but it's one click deeper....
Once in this second tier of results, using the searchbox on the page continues to bring up results that are not purely Web results, and the clue to this is a "Show web results for searchterms"
message up at the top. What Google is calling these isn't yet labeled, but they're like a deeper set of Knowledge Graph results. Once you're in them for a given city, you're in what I'm thinking of as the new Local, albeit a Local that appears to incorporate organic and has a shopping-like data feed.
You can search for movies or you can search, say, for lawyers, or whatever has a Local aspect to the area you're in, and, from a search box query, you'll get a column of results, like the old results in the left side of maps. A search for lawyers, eg, gives you a column of results on the left.
When you click on one of these Local search results, you get a wider column, essentially with a Knowledge Graph result up top, followed by rows with reviews, pictures, etc, and then ultimately organic style listings of review sites. These are all lined up in one column for smooth display on mobile. This display appears to put you back in Web results, btw, when you search again.
I'm assuming that this is the meshing of the various types of results that Pigeon was heading towards. See this discussion on Pigeon here... Pigeon Update Or Rollback Happening Now? http://www.webmasterworld.com/google/4692003.htm