Actually that's not true. [1]
In 1995 the Republican Congress repealed the 55-mile-per-hour federal speed
limit law. At the time, the highway safety lobby and consumer advocacy
groups made apocalyptic predictions about 6,400 increased deaths and a million
additional injuries if posted speed limits were raised. Ralph Nader even said
that “history will never forgive Congress for this assault on the sanctity of
human life.”
But almost all measures of highway safety show improvement, not more deaths
and injuries since 1995. Despite the fact that 33 states raised their speed
limits immediately after the repeal of the mandatory federal speed limit,
the National Highway Traffic Safety Administration reported last October that
“the traffic death rate dropped to a record low level in 1997.” Moreover, the
average fatality rate even fell in the states that raised their speed limits.
Higher speed limits have not caused one million more auto injuries. In fact,
in 1997 there were 66,000 fewer road injuries than in 1995, the year before
the speed limits were raised. The injury rate per 100 million vehicle miles
traveled fell to its lowest level ever recorded in 1997. If the injury rate
on the roads had been as high in 1997 as it had been in 1995, approximately
17,000 more Americans would have been injured on the roads.
[1] https://www.cato.org/policy-analysis/speed-doesnt-kill-repea...