The Diet passed a bill Wednesday that imposes stricter penalties on drivers who cause fatal accidents while under the influence of alcohol or drugs or due to their medical condition.

The bill, which cleared the House of Councilors and will take effect by May, was compiled in the wake of a string of fatal accidents in recent years as a result of drunken driving, unlicensed driving or driving with impaired judgment due to illness.

The new law will impose a prison term of up to 15 years for offenders who cause fatal accidents and up to 12 years for cases that result in injuries.

People with epilepsy and schizophrenia are among those subject to tougher penalties under the new law.

Stricter penalties will also be imposed on those who cause accidents while driving without a license, although this is not included in the category of reckless driving under the new law.

A charge of reckless driving resulting in death or injury carries a prison term of up to 20 years, but verifying the act as such is difficult as reckless driving is defined as a "state in which one finds it hard to drive in a normal manner."