Hmmm...so how about this...entrance path leads to main train station and no other paths from the main station to other areas...how badly would a gift shop at the main station kill the peeps desire to go on a ride to the other stations?
Peeps want to go on rides. If the only way to get on any rides is via the train, then they will use the train to get to the rides regardless of what shops you have in the entrance station. I built an entrance station like this with like 8-10 shops in it but no rides except via the train. The peeps cycled back and forth between the rides and the shops.
HOWEVER, I don't recommend building parks this way because of a strange bug with janitors and transport rides. Whenever you open a transport ride, all janitors get teleported to the park entrance. If you've given them work rosters in specific areas of the park, the janitors will try to return to their posts. But because no staff member can go on any rides (only peeps go on rides), the janitors can only get back by walking. Thus, if you don't have paths to all areas of the park, all your janitors will be stuck there at the park entrance, and litter and puke will accumulate quickly everywhere else. And the only way you can fix this is to grab each janitor with your "hand of God" control and carry each back to where he belongs, which is a pain. OTOH, if you have paths leading everywhere, the janitors will eventually find their own ways back.
In any case, there's no need to force peeps onto a transport ride. They're more than willing to use it of their own accord, PROVIDED your park design is balanced. By that I mean each area of the park has a variety of rides to appeal to all demographics. Don't put all the kiddie stuff in 1 corner and all the "big kid" stuff in another place, etc. You have to give the peeps a reason to use the transport ride, such as making it the fastest way to get between 2 or 3 widely separated rides that they want to go on. If you do that, then the transport ride is often listed as the most popular thing in the park due to the number of peeps it shuttles around.