Hey, we know that they have trucks and delivery vans and even construction equipment. What do you think the infrastructure for transport is in the setting?

4228757 Fledgling. Most things are carried by pegasi, even trucks of things by whole teams of pegasi. The idea of using an engine to haul things along the ground is just starting to be an idea, one that will serve Tumble well.

4228761 While the topic is in the air... is there something special needed to make pegasi drawn carriages safe for passengers?

4228791 Provided what's being carried is within the pegasus' carrying capacity, the magic that holds them up will hold up whatever they're hitched to, allowing a passenger to ride, provided they don't make it too heavy. This is why full chariots have teams of pegasi.

4228791 I can think of several:
Seat belts
Parachutes
Staying on the ground
Inventing the internal combustion engine