High Door Threshold as Tripping Hazard

What happens here

The cheap side entry door, common in mobile homes, features a high threshold that sticks up approximately 2.5 inches. This creates a significant tripping hazard and collects dirt easily. The host laments that 'virtually every person that walks in that building trips over the stupid threshold'. He implies that a proper commercial door would have a flush or low-profile threshold.

Goal: Avoid high thresholds that create tripping hazards and collect dirt.