¥ Shape of 2
lane highway risk curve heavily influenced
by vehicle mix and engineering practices
circa 1960Õs. Notwithstanding, Solomon's
methodology was far superior and remains
unique in this field, because he used actual
travel speeds prior to and at time of incident,
and causations. The predominantly 1950Õs vehicles
in his study were underpowered, required
significant distances for overtaking, and passing
exclusion zones etc were non existent. This is no
longer the case and risk are much lower,
except for slow moving vehicles.
¥ In all cases, once clear of conflict zones and hazards, risk from speed in and of itself is low.
¥ FHWA 1991: Only one in ten limits
are posted at or greater than the mean,
and in all cases the safest speeds are greater
than the posted limits, is still applicable.