LTSA makes much of the increase in kinetic energy of a car travelling at 120 kph compared with 100 kph.  However they totally ignore the weight of the vehicle.

Kinetic Energy = 1/2 x Mass x Velocity x Velocity

A 30 tonne truck travelling at 90 kph has the same kinetic energy as a 1 tonne small car travelling at 493 kph!

A 3 tonne utility or large SUV travelling at 100 kph has the same kinetic energy as a 1 tonne small car travelling at 173 kph.

So if there are any dangerous levels of kinetic energy on the roads, they certainly are not cars travelling at 120 kph which may have the same kinetic energy as a 30 tonne truck travelling at only 22 kph or as a 3 tonne vehicle travelling at just 70 kph.

Was this just ignorance, or deliberately misleading?  It is hard to believe that even LTSA has no staff sufficiently educated to detect this blatant scientific fallacy.

The following table adapted from a US Dept Of Transportation National Highway Traffic Safety Administration study shows some typical vehicle classes and weights and the corresponding speeds at which these weights have equivalent kinetic energy.

TABLE 3 - ADJUSTED FATAL-CRASH INVOLVEMENT RATES PER BILLION CASE VEHICLE MILES, BY VEHICLE TYPE
(Case vehicles are Model Year 1996-99 light trucks and 4-door cars with air bags in Calendar Year 1996-2000, adjusted for age/gender, rural/urban, day/night, speed limit, and other factors)
Vehicle Type and Size	Average Curb Weight (Tonnes)	Average Curb Weight (lbs)	Average Prorated* Fatal Crash Involvements Per Billion Miles	Speed of 1 tonne car with same kinetic energy as this at 100 km/h
Very small 4-door cars	0.95	2,105	15.73	98
Small 4-door cars	1.12	2,469	11.37	106
Mid-size 4-door cars	1.39	3,061	9.46	118
Large 4-door cars	1.63	7.12	128
Compact pickup trucks	1.51	3,339	11.74	123
Large (100-series) pickup trucks	2.02	4,458	9.56	142
Small 4-door SUVs	1.43	3,147	10.47	119
Mid-size 4-door SUVs	1.82	4,022	13.68	135
Large 4-door SUVs	2.33	5,141	10.03	153
Minivans	1.79	3,942	7.97	134

This data is also shown in the following chart:

The crash involvement data reflects the fact that heavier vehicles are less likely to kill their occupants but more likely to kill occupants of another vehicle they may hit.  Mid-range SUVs have unexpectedly high fatality involvement which may reflect both instability and unequal height issues.