A major alpine transit route through western Austria was partially shut to traffic on Friday, as part of a protest against excessive heavy transport and resulting pollution.

The one-mile stretch of motorway between Vomp and Schwaz was shut at 11:00 am (0900GMT) for 12 hours due to the action, which was sanctioned by the authorities.

The Transitforum initiative, which planned the operation, is calling for stricter speed limits and the reimposition of a sectoral traffic ban in the Inn valley in Austria's western Tyrol province, a key axis between Germany to the north and Italy to the south.

Austria already imposed banson this route for certain types of lorries a few years ago, but the European Commission ruled that they violated the free movement of goods.

Proponents of sectoral bans point to studies that showed the levels of nitrogen oxide in the Inn valley surpassed legally acceptable levels by up to 120 percent.

Vehicles were diverted Friday on to secondary roads but heavier transport was advised to take alternate routes via Switzerland or the Tauern tunnel further east.