Parking lot drainage design

This is what the AASHTO Guide for Design of Park & Ride Facilities says:

5.7 DRAINAGE REQUIREMENTS
Adequate slope should be provided to surface lots in order to minimize the possibility of low or flat
spots. Ponding of water in a lot is undesirable both for vehicle and pedestrian movement. This is particularly
true in cold climates where freezing may create icy spots. Surface drainage should be designed to avoid
water collection in areas where pedestrians walk or stand.

Curb, gutter, and surface area drains and grates should be installed where needed to collect and direct
water and minimize water drainage across primary pedestrian routes. In pedestrian and bicycle traffic areas,
only drainage grates with short, narrow openings, placed perpendicular to traffic flow direction, should be
used to minimize the hazard and allow safe passage over the grate. When possible, drainage inlets should
be located away from high pedestrian and bus loading locations.

Where possible, the pavement in the bus loading area should be sloped away from the loading zone
curb to prevent water from splashing on waiting patrons. However, the grading must be consistent with
the need to provide handicapped access from the passenger loading pad to bus lift platform.

Water retention/detention facilities and environmental controls for runoff water quality should be designed
in accordance with state and local regulations and standards.

Attached is a paper I had in my files. It's more specific than the AASHTO guide.