This refers to a test for a cars ability
to avoid a hypothetical moose
in the road.
The premise is that in Sweden (where this test is required) it is possible for a moose to jump out into the road an become a dangerous obstacle. The car needs to be able to approach the 'elk' at a minimum of 37mph(60kph) and be able to swerve out of the way safely. It was introduced after a managing director at SAAB was killed when his car collided with an elk.
The test was made famous in October 1997 by the dramatic failure of the Mercedes A class that ended with the car on it's roof. The test is a particular problem for vehicles with a high centre of gravity which are more likely to have tyres leaving the road surface as the car rolls in the turn.