Hello Katrina and thanks for asking the Disney Parks Moms Panel such an important question.
While I understand completely why folks would think that it is indeed possible for Guests to walk between Resorts or Theme Parks while on vacation at Walt Disney World Resort it is not something I would wish to undertake with my own family.
All Cast Members are simply
Wild About Safety and as you will see from this
Map of Walt Disney World Resort on foot Disney's Typhoon Lagoon Water Park is a reasonably long distance away from the Downtown Disney Area along a very busy road; therefore in my opinion making this journey somewhat perilous.
So if not utilising the complimentary
Walt Disney World Bus Service from Disney's Typhoon Lagoon Water Park why not consider hiring a taxi cab to arrive safely on time at
T-REX for your Advanced Dining Reservation at 3pm.
If I can help sprinkle any extra pixie dust onto your upcoming visit to Walt Disney World Resort please pop back to ask me another question.
Have a great Disney day.
~ Jane