DUI Laws: Implied Consent to Search on the Roadway - An Overview

Pennsylvania, like many other U.S. states, has an implied consent law.

The concept of implied consent is that a driver consents to a search to chemical testing of blood, breath, or urine for a Blood Alcohol Concentration (BAC) upon suspicion that the individual is driving while under the influence.

Since all Americans enjoy a freedom from unreasonable searches and seizures pursuant to the Fourth Amendment, law enforcement’s authority to conduct searches cannot be absolute. But before getting into the state of the exiting law, it is useful to explore how this concept became incorporated into American Law.

Decades ago, motorists detained or arrested under suspicion of Driving Under the Influence would often refuse any chemical testing to establish a BAC. This meant that authorities had a difficult time in successfully prosecuting DUI-related offenses. Importantly, as mentioned in a previous post, the presence of chemical testing does not necessarily make a DUI offense unpunishable. In the absence of chemical testing, law enforcement officers can and do rely on commonsense observations about the individual and what has occurred in the particular incident. 

In reaction to motorists refusing blood tests, states began enacting implied consent laws - effectively, a legislative waiver of a motorist’s right against unreasonable searches. At least in theoretical terms, the concept of implied waiver is that of a bargain:  effectively, in exchange for using the roadway, a motorist consents to a chemical search to ensure that the motorist is using the roadway safely.  This bargain / legislative waiver has generally been considered both palatable for a people who traditionally enjoy robust rights against government intrusion of any type.  Even more so, it has been considered a tool for good to enable law enforcement to help curb the epidemic of DUI-related accidents and deaths.  This does not mean, however, that the implied consent statutory regime has not had its critics.  Pennsylvania first adopted its implied consent law, which is codified in the Motor Vehicle Code, Title 75 of the Pennsylvania Consolidated Statutes, Section 1547 (properly cited as 75 Pa.C.S. § 1547).

The Federal Government also encouraged the proliferation of the implied consent statutory regime. Through the passage of the National Traffic and Motor Vehicle Safety Act of 1966, Congress incentivized states to adopt implied consent laws.

The U.S. Supreme Court has also generally upheld implied consent laws as constitutional, though the broad authority assumed by state actors under the law has been narrowed by the Court in the ensuing decades. In the landmark case of Schmerber v. California, 384 U.S. 757 (1966), the U.S. Supreme Court held that a warrantless search of a motorist’s person did not violate the Fourth Amendment. Under this regime, it was lawful for state actors to forcibly withdraw blood from a motorist suspected of a DUI offense.

In the landmark case of Birchfield v. North Dakota, 579 U.S. ____ (2016), the U.S. Supreme Court dealt a blow to implied consent laws by holding that warrantless searches of a motorist’s breath are permissible under the Fourth Amendment’s right against unreasonable searches and seizures; however, warrantless searches of a person’s blood, which requires the intrusive act of blood collection, are not permitted.  However, even in the latter category of searches, the exigent circumstances exception and other exceptions may still permit collection of blood samples.

Birchfield is generally credited with upending many of the states’ implied consent statutory regimes because of the practical difficulties of obtaining a warrant when BAC rather quickly dissipates from the human body.

Nevertheless, Birchfield did not have the practical effect of stripping law enforcement of the ability to enforce DUI laws. The primary enforcement mechanism used to ensure that individuals consent to a chemical testing of blood after being arrested for suspicion of DUI is the threat of civil license suspension. In Pennsylvania, for instance, refusing a blood test results in an automatic 12-month suspension of the motorist’s driving license. For a subsequent refusal, an 18-month suspension may be imposed. Hence, while Birchfield practically makes evidence collection for a DUI prosecution more burdensome, through license suspensions, state governments nevertheless are equipped with a powerful enforcement mechanism to keep drunk drivers off the road: license suspensions.

Adding to the already complicated statutory scheme and enforcement mechanisms therein, a license suspensions is technically a civil - not criminal - matter, though they are a crucial tool in effectuating the aims of the criminal penalties set forth in the DUI-related offenses (75 Pa.C.S. § 3802 et seq). The co-mingling of civil with criminal matters is problematic, most especially since the government generally cannot threaten to revoke a civil benefit in order to obtain a waiver of a constitutional right. This rule, which has found its way into many legal opinions in many different contexts, is known as the Unconstitutional Conditions Doctrine. For example, in Nollan v. Cal. Coastal Comm’n, 483 U.S. 825 (1987), the U.S. Supreme Court held that it was unlawful for a government entity to condition the issuance of a building permit upon the granting of a public right-of-access across the applicant’s property, as it violated the Fifth Amendment’s Takings Clause.

Using threat of civil suspension of a motorist’s license in order to compel or coerce a chemical blood test plainly appears to invoke the Unconstitutional Conditions Doctrine. In a 2017 Commonwealth Court (one of the two appellate courts in Pennsylvania’s court system) opinion in Marchese v. Commonwealth, 169 A.3d 733 (Pa.Cmwlth. 2017) the Court stated that the process of threatening to suspend a license in order to obtain consent for a chemical test does not violate the Unconstitutional Conditions Doctrine because, among other reasons, “[i]t is well settled in Pennsylvania that driving is a privilege, not a property right.” 169 A.3d at 740 (bold emphases underlined added).

The Marchese opinion perhaps does not fully address the Unconstitutional Conditions Doctrine in that the right versus privilege paradigm probably does not capture the totality of the cases that have traditionally been considered the basis of the Doctrine. Regardless, the practical reality is that if law enforcement were stripped of the ability to threaten a license suspension for avoiding a test, states would lose what is perhaps the most meaningful enforcement mechanism to keep drunk drivers off the road.  It is fair to say that the decision could be explained by the state’s significant need to enforce the DUI laws, and it is also fair to speculate that where the governmental interest is less significant in other contexts, our courts may be more inclined to restrain government conduct through the Unconstitutional Conditions Doctrine.

In summary, there is a long technical history of the states’ statutory schemes to enforce their various DUI laws which mirror the complexity of many of these statutes themselves. Modern DUI regulation can be seen as a compact between states and individual motorists - a bargain that requires agreement to chemical testing in exchange for use of the roadways themselves, an idea expressed in the term of Implied Consent.  It also involves matters which are criminal and civil, but intermixed to such a degree that it is sometimes difficult for even legally trained minds to tell where one ends and the other begins, and thusly gives rise to the same kinds of concerns that underpin the Unconstitutional Conditions Doctrine. Above all, the enforcement mechanisms designed to keep drunk drivers off the road represents a long evolution of enacting policies out of a very real concern for public safety, all the while keeping honest with one of our most important rights against government overreach: the right against unreasonable searches and seizures, as set forth in the Fourth Amendment of the U.S. Constitution and Article I, Section 8 of the Pennsylvania Constitution, respectively.