This animation is based on a surface contamination research study. It is not in a busy restaurant but rather a busy hospital area. How different would this be in a restaurant? Perhaps some university can conduct something similar in a foodservice environment.
Pathogens do get around and hands are the dominant transfer vehicle. This information speaks volumes in encouraging frequent use of hand sanitizers and clean-as-you-go surface cleaning protocols. The researchers seeded the telephone in POD D of this intensive care unit with an easy to detect, inert DNA material (red dot) and then tracked it's movement over the 8 hours of a single shift. Every 2 hours 32 swabs were done in each of the patient pods and 10 swabs in each of the staff common areas. Nurses were confined to one patient POD but could move freely to the common areas. Doctors, specialists and support staff could move as required. Obviously the patients weren't mobile, they were just the victims of poor hand and surface hygiene.
Before you start, take a guess at what area was most contaminated after the 8 hours? Is there a similar high-touch location in your restaurant?
More detail is available at http://pediatrics.aappublications.org/content/105/2/311.abstract