Austria has announced it will introduce quotas to limit the incoming flow of migrants.
The news comes days after the Foreign Ministry said the country was already close to reaching the maximum number it said it would accept this year.
Fears are growing of a potential end to the open-border Schengen zone and the subsequent threat to free travel.
Road haulier Alexander Klacska explained.
“For us in the Austrian transport industry, the worst case scenario would be that if the Schengen borders around Austria close, it would cost us up to 8.2 million euros per day."
Increased checks are already in place at the busiest crossing, Spielfeld, on the border with Slovenia. Vienna says it will tighten border controls at 12 further points.
Government officials claim other countries along the Greece-to-Austria Balkan route are also increasingly tightening checks.
Austria's Interior Minister Johanna Mikl Leitner said daily and hourly quotas would be introduced. She added that border authorities would stop letting people through once the limits are reached, although she did not specify the size of the quotas.
Mikl Leitner said Germany had had a similar system in place on its border with Austria for months. It has caused backlogs and delays in Austria.
The Interior Minister said something similar could be expected in Slovenia.