The world's first tax on heavy goods vehicles, introduced by the Swiss six months ago, should meet its income target, according to the federal customs office. But the levy has failed to encourage significant numbers of hauliers to transfer freight from road to rail.
Truck companies are expected to fork out SFr750 million ($424 million) in taxes by the end of the year.
Foreign truckers paid SFr79 million in the first five months of year to use Swiss roads, according to the customs office. By contrast, Swiss hauliers forked out SFr44 million in the month of January alone to deliver their goods by road. Figures for subsequent months are not yet available.
The tax is based on the polluter-pays principle. Foreign trucks can either have an electronic identification card or carry a control device, as their Swiss counterparts do.
So far, around 1,000 foreign vehicles are using the device. This means the terminal system set up at the border to register the tax owed is working well, according to Hans Hausler of the customs office.
The Road Haulage Association says the system is working better than it expected, even if it entails longer delays at the border. But billing remains a problem because of a lack of manpower, according to Beat Keiser, the association's spokesman.
Some companies have received their bills up to two months late. The customs department lays some of the blame on external factors.
"The cantonal vehicle registries have often supplied us with incomplete data," said Hausler. "Our computer services are also lacking coordination."
The road hauliers had warned of increased prices for consumers before the introduction of the tax. They estimate the cost per year is equivalent to SFr250 for each household, but the customs services say they have seen no pressure on pricing.
The new tax seems to have failed so far to achieve its goal of encouraging hauliers to load their trucks on to trains for the journey across the Alps. Traffic through the Gotthard tunnel continued to grow throughout the first part of the year.
"It seems the introduction of the tax and the increase of the weight limit for trucks along this route at the same time have cancelled each other out," said Christian Küng of the Federal Office for Spatial Development.
The tax does appear to have reduced the number of empty trucks using the north-south corridor through Switzerland, though.
It may have also influenced a trend noticed by the railways: namely that hauliers are using rail to carry light, bulky loads, while relying on the roads for the transport of heavier goods. According to Jean-Daniel Blanc of the railways cargo division, this is due to the newly increased capacity of trucks.
swissinfo with agencies