Fares on red minibus routes that pass through the Western Harbour Tunnel may be raised in two weeks after a set of new tolls took effect yesterday. Operators of seven minibus routes will meet today to discuss the increase, expected to be between 50 cents and HK$1. Lai Ming-hung, of the Taxi and Public Light Bus Concern Group, said drivers would have to pay up to HK$1,500 a month in extra costs if they did not raise fares. 'Still, I think five of the seven routes that now pass through the Western Harbour Tunnel may swallow the extra costs, because many of their services overlap that of buses.' Traffic at the Western Harbour Tunnel was scarce yesterday morning, although not much different from a usual Sunday, when the toll for cars and taxis increases by HK$5 to HK$50 and HK$45, respectively. The Transport Department expects the toll rise to push about 2,600 vehicle trips a day to the already congested Cross-Harbour Tunnel and Eastern Harbour Tunnel, but the League of Social Democrats said that will not be the only impact. 'The toll rise sets a very bad example for other public utilities. Taxis, buses and minibuses have all applied for fare rises,' said the league's Edward Yam Liang-hsien. League members joined a slow-drive protest yesterday. The convoy stopped at the tunnel's toll plaza on the Kowloon side and submitted a petition to the operator demanding that the toll rise be suspended. Authorities were still assessing an application by taxi drivers to increase fares. This would add HK$2 to the flag-fall price, which is currently set at HK$18. Kowloon Motor Bus applied for an increase of up to 8.6 per cent the day Western Harbour Tunnel announced its toll rise. Taxi and KMB fares were last raised about two years ago. The government said in March that the Cross-Harbour Tunnel's toll - the cheapest of the three crossings - may have to be adjusted. More than 120,000 vehicles use the Cross-Harbour Tunnel each day -the same volume as the other two tunnels combined. The Democratic Alliance for the Betterment of Hong Kong said it may advise the government to build a fourth crossing to alleviate tunnel traffic or build an extension that branches off from the Cross-Harbour Tunnel to Central. The government is expected to release findings of a study on ways to regulate tunnel traffic before the end of the year.