I've seen this come up on This Thread that people would like to see a Travel & Survival book, and I'm curious as to what people would want to see in it? What do people consider wrong or needing changing? What's missing?

I would like the book to cover how to make this part of the gameplay play a larger role, such that encumbrance and path finding becomes relevant in campaigns on an equally footing with other character aspects.

I use skill challenges for travel in the wild, but it's all seat-of-the-pants stuff I have to completely homebrew. I would love a chapter with reference material and ideas I could use to make the skill challenges more interesting/varied/unique.

I'd like to see an expansion of the Adventure Environments section of the DMG and the Wilderness Kit. More environmental hazards, encounters, and possibly mini-adventures for each of the unusual environments would be nice. Perhaps the same treatment for inner and outer planes as well. I like the random encounters appendix in Tomb of Annihilation. I think something similar to that for different environments would be cool, especially the tables for treasure drops and dead explorers.

Descriptions and rules for various methods of long distance travel for encounters while traveling in such ways. Sailing ships and airships and dealing with pirates, monsters of the deep, and other things they might encounter on their voyages. Fantasy submarines with magic airlocks and spells and magic items for exploring the bottom of the ocean. Caravans and the monsters, bandits, and environmental hazards they can encounter in various environments like deserts, jungles, arctic tundra, mountains, or temperate forests (including specialized wagons, mounts, and beasts of burden for such environs). Plus, of course, the examples of native peoples or abandoned and monster-ridden ruins that could be found on a floating sky island in the clouds, at the bottom of an oceanic trench, at the north pole, deep within a dark and trackless jungle, etc.