The courts would be able to order drivers jailed and disqualified for serious traffic offences to start serving their driving bans after their release under new proposals floated yesterday. The plan, one of a fresh batch of measures to crack down on bad drivers, would address concerns that under the current practice - whereby the sentence and the ban are served concurrently - a person may be able to drive immediately after walking free. When the Transport Advisory Committee discussed the proposal on June 30, questions were raised about whether enforcing the two penalties separately might amount to a double penalty for the same offence. But the government believes this should be left for the courts to decide. The move follows the recent case of a driver jailed for last year's Sai Kung bus crash that killed 19 people, in which the presiding District Court judge ordered the man to sit a certification examination before he could drive again. Hung Ling-kwok, 33, was sentenced to three years and four months' jail last month on one count of dangerous driving causing death and was banned from driving for three years. He would have been able to drive again immediately after leaving jail if the judge had not imposed the examination order. Other measures revealed yesterday in a Legislative Council paper include removing an option for drivers whose initial road-side breath test shows an alcohol level less than 37 micrograms per 100 millilitres of breath to replace the result with a urine or blood test taken some time later at a police station. Officials argue that will help plug a loophole that now allows drivers to buy time while the level of alcohol in their blood falls. The legal limit is 22 micrograms per 100 ml of breath. The deputy chairman of the Legislative Council's transport panel, Andrew Cheng Kar-foo, welcomed both proposals, saying they would deter people from drink-driving. The amended legislation will be introduced in the new legislative year after lawmakers, the Road Safety Council and the transport trade are consulted in the next few months. The proposal also includes a new three-tier penalty scheme in which the disqualification period for a driver would be set according to his or her alcohol level. The minimum disqualification for drink-driving and dangerous driving offences will be increased to two years upon first conviction and five years upon second conviction. Drivers in fatal accidents whose alcohol level is three times the limit will have an extra 50 per cent applied to their sentence under a measure that treats drink-driving as an aggravating factor for dangerous driving causing death. That would push the top penalty from 10 to 15 years.