Proof of Impairment by Alcohol (Prior to December 13, 2018)
The Crown need only prove any degree of impairment of the person's ability to drive, not matter how great or minor. 
Impairment refers to the physiological effect of alcohol upon the mind. This is separate from intoxication, which refers to the observable physical signs of impairment. 
Note, however, impairment is relative to a particular task. It is not simply a degree of general impairment but rather the accused's ability to drive is impaired and that the impairment is caused by alcohol or a drug. The judge should not assume that mere impairment of any functional ability is equivalent to impairment by alcohol. here fatigue is combined with alcohol, the only issue is whether the alcohol was a contributing factor to the impairment.
- Burden and Standard of Proof
Impairment must be proven beyond a reasonable doubt.
R v Stellato, 1993 CanLII 3375 (ON CA), (1993), 78 CCC (3d) 380 (Ont. C.A.), per Labrosse JA; affirmed 90 CCC (3d) 160 (SCC), 1994 CanLII 94 (SCC), per Lamer CJ
R v Brannan, 1999 BCCA 669 (CanLII), (1999), 140 CCC (3d) 394, per Donald JA ("the test for driving while impaired contrary to s. 253(a) is any impairment")
see also R v Pijogge, 2012 NLTD(G) 94, 2012 CanLII 35597 (NL SCTD), per Stack J
R v White, 2004 NLSCTD 9 (CanLII), (2004), 50 M.V.R. (4th) 177 (NLSC), per LeBlanc J
R v Loveman, 2005 NLTD 51 (CanLII), (2005), 15 M.V.R. (5th) 280 (NLSC), per Schwartz J
R v Thompson, 2012 ONCJ 377 (CanLII), per Nadel J, at para 13
- See R v Andrews, 1996 CanLII 6628 (AB CA),  AJ No 8 (ABCA), per Conrad JA in the analysis section discussing this difference
- As observed in R v Raven,  OJ No 48 (Gen. Div.)(*no CanLII links) , per Durno J, at paras 47 and 50: it is incorrect to read Stellato as requiring only proof of a slight degree of impairment by alcohol as opposed to a slight degree of impairment of one’s ability to operate a motor vehicle as a result of the consumption of alcohol
Andrews, supra, at para 17 (Courts "must not fail to recognize the fine but crucial distinction between ‘slight impairment’ generally, and ‘slight impairment of one’s ability to operate a motor vehicle.")
R v Sampson, 2009 NSSC 191 (CanLII),  NSJ No. 280, per Beveridge J
R v Christopher, (1982) BCJ No. 2008 (BCCA)(*no CanLII links)
, at para 2-5
R v Pelletier, 1989 CanLII 4823 (SK QB), (1989) SJ No. 493 (Sask. Q.B.), per Batten J
R v Payette, 1991 CanLII 1746 (BC SC), (1991) BCJ No. 795 (BCSC), per Cowan J, at paras 2 to 3
R v Barry, 1991 CanLII 2377 (BC SC), (1991) BCJ No. 2212 (BCSC), per Cohen J
R v Bartello, (1996) OJ No. 1000 (OCJ)(*no CanLII links) , appeal dismissed, (1997) OJ No. 2226 (ONCA), 1997 CanLII 1025 (ON CA), per curiam, at 22
R v Isley, 1997 CanLII 1459 (BC SC), (1997) BCJ No. 2678 (BCSC), per Sigurdson J, at para 23
R v Cosentino, 2008 CanLII 68102 (ON SC), (2008) OJ No. 5263 (ONSC), per Durno J at 54, 92-93
R v Czarnecki, 2000 MBQB 42 (CanLII), 2000 Carswell Man. 215 (Q. B.), per Hamilton J
R v Stellato, 1994 CanLII 94 (SCC),  2 S. C. R. 478, per Lamer CJ
To prove any degree of impairment of ability to drive, the crown should present evidence of aberrant driving and consumption of alcohol. If evidence of driving is not available there is greater responsibility of establishing impairment through signs of the accused.
Impairment cannot be inferred merely by the readings from the breath sample results. A judge cannot take judicial notice that a certain reading necessarily means that the person is impaired.
It is not necessary to prove that the driver intended to become impaired. Proof of the actus reus alone is sufficient to create a presumption that the accused intended to operate while impaired.
Where the evidence of impairment is equivocal on the totality of evidence, it would be dangerous to conclude beyond a reasonable doubt that there was impairment. This would include circumstantial evidence alone or equivocal evidence of impairment that shows only a “slight deviation from normal conduct”.
- Odour of Alcohol Alone
The odour of alcohol alone is not sufficient evidence to support a finding of impairment. It is not criminal simply to consume alcohol and driving. The judge instead must consider the "totality of the evidence" to determine impairment.
- Circumstances and Timing of Observations
Observations of an accused made during their compelled participation in an investigation, such as during pullover investigative detention, cannot be admissible for the purpose of proving impairment as it in only admissible for proving the officer's grounds.
- Observations While Performing Sobriety Test
Any observations made while an accused is performing a mandatory sobriety test cannot be used to prove impairment because it is a compelled and violates the rule against self-criminating evidence.
R v Polturak, 1988 ABCA 306 (CanLII), (1988), 90 A.R. 158, 61 Alta. L.R. (2d) 306 (C.A.), per Stratton JA, at para 3
R v Beals (1956), 25 C.R. 85, 117 CCC 22 (NSCA), 1956 CanLII 534 (NS SC), per Doull J
R v E(AL), 2009 SKCA 65 (CanLII), 359 Sask. R. 59, per Wilkinson JA
R v Thomas, 2012 SKCA 30 (CanLII), per Caldwell JA, at para 13
- see R v Letford, 2000 CanLII 17024 (ON CA),  OJ No 4841 (C.A.), per Goudge JA
R v Pomeroy, 2007 BCSC 142 (CanLII),  BCJ No. 170 (S.C.), per Romilly J, at para 44
R v Mavin, 1997 CanLII 14625 (NL CA), (1997), 154 Nfld & P.E.I.R. 242, per Marshall JA, at para 37
R v King, 1962 CanLII 16 (SCC),  SCR 746, per Ritchie J
R v Lamha, 2011 ABPC 303 (CanLII), per Rosborough J -- impaired by a mix of drugs
- R v Peterson, 2009 ONCJ 61 (CanLII),  OJ No. 671, per Green J at 35 citing R v Andrews, 1996 CanLII 6628 (AB CA), per Conrad JA
- Andrews, ibid.
R v Uduma, 2019 ONSC 2350 (CanLII), per Barnes J, at para 28 ("The odour of alcohol alone is insufficient to support a finding of impairment")
R v Landes (1997), 1997 CanLII 11314 (SK QB), 161 Sask. R. 305, per Klebuc J, at para 21
R v Hawkins,  O.J. No. 3446 (C.J.)(*no CanLII links) , at para 38
R v Logan, 2006 CanLII 20536 (ON SC),  O.J. No. 2445 (S.C.), per Tulloch J
R v Martin, 2016 ONCJ 799 (CanLII), per Bourgeois J, at paras 41 to 42
Uduma, supra, at para 28
Andrews, supra, at para 28
- R v Phipps, 2010 ABQB 661 (CanLII), per Moreau J
R v Uduma, 2019 ONSC 2350 (CanLII), per Barnes J, at para 36 ("An observation made while an accused is taking a sobriety test is inadmissible at trial because the accused has been compelled to participate in activity that produces self-incriminating evidence")
R v Milne (1996), 1996 CanLII 508 (ON CA), 28 O.R. (3d) 577 (C.A.), per Moldaver JA, at paras 40 to 47, leave to appeal to SCC refused,  S.C.C.A. No. 353
R v Quenneville, 2009 ONCA 325 (CanLII), per curiam
R v Brode, 2012 ONCA 140 (CanLII), 109 O.R. (3d) 481, per Epstein JA, at paras 57 to 63
R v Bijelic, 2008 CanLII 17564 (ON SC),  O.J. No. 1911 (S.C.), per Hill J, at para 31
Physical Signs of Impairment
Factors to consider include:
- erratic or abnormal driving
- blood-shot or watery eyes
- flushed face
- odour of alcoholic beverage
- slurred speech
- a deterioration of the accused’s judgement, attention, or comprehension
- a loss of motor co-ordination or control,
- increased reaction times,
- diminished sensory perceptions, or
- inappropriate or abusive behaviour
Observations of impairment:
|Odour of alcohol||Faint
Field Sobriety Tests
Section 254(2.1) permits the police to make a video recording of the test:
Evaluation for drugs has similar requirements as 254(2) and (2.1) found in (3.1) and (3.2).