Backgrounder for former Bill C-46, An Act to amend the Criminal Code (offences relating to conveyances) and to make consequential amendments to other Acts, as enacted


Driving while impaired by alcohol or a drug and dangerous driving kill and injure thousands of Canadians every year and impose enormous social and economic costs on society. It is the leading criminal cause of death and injury in Canada. The criminal law has long recognized the potential devastating impacts of impaired driving. Canada first prohibited driving while intoxicated in 1921. In 1925, a drug-intoxicated driving offence was enacted. Since that time, there have been numerous amendments to the transportation offences, most frequently in the area of impaired driving.

While these periodic reforms strengthened measures to combat impaired driving, they also added to the complexity of the Criminal Code’s transportation offence provisions and created some overlap between offences and inconsistencies amongst penalties. Moreover, the impaired driving provisions have been subject to such extensive litigation that it is difficult in some cases to understand how they operate from simply reading the text. This, in turn, has impacted effective and efficient investigation, prosecution and sentencing.

The Government introduced Bill C-46, An Act to amend the Criminal Code (offences relating to conveyances) and to make consequential amendments to other Acts (the Act) on April 13, 2017 to modernize, simplify and strengthen these provisions as well as to create new and stronger laws to combat drug-impaired driving, in advance of cannabis legalization. The Bill received Royal Assent on June 21, 2018.

The Act is divided into three parts:

Part 1 aims to strengthen the criminal law approach to drug-impaired driving. It does this in a number of ways, including the creation of blood drug concentration (BDC) offences (with the prohibited drug levels being set by regulation) and the authorization of roadside drug screening using approved drug screening equipment (ADSE). It amended the existing Criminal Code transportation regime, and as such, did not change the numbering or structure of the transportation regime. Part 1 came into force on Royal Assent (June 21, 2018), which was ahead of legalization of cannabis in October 2018. The regulation setting the prohibited levels of impairing drugs came into force on June 26, 2018.Footnote 1

Part 1 of the Act was subsequently repealed and replaced 180 days later on December 18, 2018, when Part 2 of the Act came into force. As such, the changes made in Part 1 have now been superseded by the amendments in Part 2. Part 2 of the Act repeals all of the current transportation offences and enacts a new Part VIII.1 of the Criminal Code (Offences Relating to Conveyances). The changes made in Part 1 were incorporated into Part 2. It aims to facilitate the detection and investigation of alcohol and drug-impaired driving; facilitate the prosecution of impaired driving; reduce court delays; and simplify and modernize the Criminal Code transportation regime. While much of the new Part will be familiar to criminal justice practitioners, the drafting has been modernized and simplified. In addition, the provisions have been organized in a coherent manner: definitions and interpretation; penalties and prohibitions; investigative matters; evidentiary matters; and general provisions. Notwithstanding the significant overhaul, much of previous jurisprudence will remain relevant and can continue to be relied on. This Backgrounder attempts to specifically indicate where this is the case.

In addition to the modernization and simplification of the drafting in Part 2, there have been some key policy changes: the authorization of mandatory alcohol screening (MAS); elimination of the “bolus drinking” defence; limitation of the “intervening drink” defence; facilitation of the proof of blood alcohol concentration (BAC); clarification with respect to certain elements of disclosure; and raising some mandatory minimum fines and maximum penalties. Part 2 of the Act came into force on December 18, 2018, which was 180 days after Royal Assent. This extra time was requested by provinces and territories to have adequate time to prepare for its implementation given the scope of the proposed reforms. As Part 1 was already in force, this allowed increased time for the implementation of Part 2, while still ensuring that a robust drug-impaired driving regime was in place to address any increase of drug-impaired driving that would occur as a result of the legalization and regulation of cannabis.

Part 3 outlines the coming into force of the Act.

All of the changes are intended to have a positive impact on road safety by reducing deaths and injuries caused by drinking or drug-using drivers and to facilitate the resolution of impaired driving criminal trials. As indicated by the former Minister of Justice and Attorney General of Canada during Second Reading debate in the House of Commons on Bill C-46, “I introduce the bill with the ultimate goal of reducing the significant number of deaths and injuries caused by impaired driving, a crime that continues to claim innocent lives and wreak havoc and devastation on Canadian families.”Footnote 2

For further information, Canadians may wish to consult the information on the Parliament of Canada website on former Bill C-46 which includes links to major speeches and to committee proceedings in the House of Commons and the Senate, available at:

Date modified: