Warning
Warning
[An American Diamond warning sign with the following message on it:] You're in a box on wheels hurtling along several times faster than evolution could possibly have prepared you to go Next 5 miles

This parody of a road sign essentially reminds drivers of the reality of the situation they are now in and thereby implicitly refers to the dangers inherent to it. Because the ability to travel in a box on wheels at  high speeds was not selected for in the evolution of human, if anything happens to said box on wheels, such as crashing into a wall, the humans inside may be badly injured, if not killed. Had they evolved something like exoskeletons, for example, this may not have been the case. This reminder would presumably prompt drivers to drive more carefully or perhaps slow down.
Humans did not evolve to have the ability to withstand such forces because their ancestors commonly never traveled any faster than about 20 km/h (top human speed on foot), although some individuals may have moved faster than that by falling out of a tree or off a cliff. Fast vehicles, on the other hand, have only appeared in the last couple of hundred years, and it would take many more tens or hundreds of thousands of years before these new selection pressures made any noticeable difference to human physiology, if any.
The road sign is far too lengthy and philosophical to be used in practice but is conceivable as an advertisement for safe driving.
The phrase "next 5 miles" is common to road signs, particularly those on US highways in rural areas. This is to indicate that the conditions on the sign will continue for the next five miles along that road.
The title text refers to the fact that the sign doesn't really know how many more miles the driver may travel, and that it may be more than five. Since the average American drives over 13,000 miles per year , this is indeed very likely.
[An American Diamond warning sign with the following message on it:] You're in a box on wheels hurtling along several times faster than evolution could possibly have prepared you to go Next 5 miles
