The Swiss environmental organisation, Alpine Initiative, has called for faster action to reduce the number of heavy goods vehicles clogging Swiss roads. It is seeking to move more freight traffic off the roads and on to the country's railways.
At a press conference on Thursday, members of the Alpine Initiative criticised the government for easing of weight limits for trucks at the beginning of the year, which has led to an increase in road traffic.
The amount of freight carried on the railways has also increased, but still lags far behind road transport.
It also called on the government to put pressure on neighbouring Italy to upgrade its rail network to make the Trans-Alpine passage more efficient, and reduce pollution on highways linking the two countries.
The Swiss transport minister, Moritz Leuenberger, has said trains carrying heavy goods vehicles will be able to use the Lötschberg and Simplon tunnels, which link Switzerland and Italy, from June.
The Alpine Initiative endorsed the government's policy of taxing heavy good vehicles on Swiss roads, following the imposition of a levy at the beginning of this year.
The tax, the first of its kind in the world, affects all Swiss roads, not only major highways and takes into account the weight, emissions and kilometres clocked up by the vehicle.
A spokesman for the Alpine Initiative, Jan Gürke, said the levy is helping to "control trucks which are going too fast and transporting too much".
Stephanos Anastasiadis, of the European Federation for Transport and Environment, also supported the tax. He told swissinfo that other European countries can learn from the Swiss initiative.
"As opposed to the existing system in Europe, this tax doesn't cover just the motorways. So truck drivers who decide to take a secondary road can't escape paying. This means they'll use the fastest route possible, avoiding the smaller roads in heavily populated areas, and reducing levels of pollution."
swissinfo with agencies