A finished-looking pad is not a finished pad
Freshly graded ground looks flat and drives well in the dry. It has not consolidated, and after rain a slab machine with small solid tires and a few inches of ground clearance will bog down within a few feet.
This is the most common reason a scissor lift booking is wrong. If the concrete is not poured, book rough terrain.
What Texas soils do
The Gulf Coast has soft clay fill and a high water table: bearing capacity falls dramatically when it is wet, and outrigger pads matter more than people expect.
The Blackland Prairie through Dallas, Fort Worth and the mid-cities is expansive clay that carries load well when dry and turns greasy within hours of rain.
Hill Country limestone around Austin and San Antonio is firm and close to the surface, which is excellent for outriggers and awkward for anything that needs pinning. West Texas and the Panhandle are firm caliche, with dust as the operational problem.
Slope, and why it is stricter than it looks
Scissor lifts have tight slope tolerances, often only a couple of degrees, and are generally not to be elevated on a grade at all. Rough terrain machines have levelling and more tolerance, but the limit is still on the data plate rather than in the operator's judgement.
What is under the ground, not just on it
Backfilled trenches, basements, vaults, septic systems and underground utilities can all fail under a point load that the surface carries fine. For crane work this is a formal duty of the controlling entity; for a heavy telehandler it is just as real and far less often checked.
The five-minute check before you book
What is the surface: concrete, compacted base, or graded dirt? Is there a slope? Are there drop-offs, trenches or covers? What is the narrowest point on the route in, and how high is the lowest overhead? Where can a lowboy actually stop to unload?
Five answers, and they determine the machine, the delivery charge and whether the day goes to plan.