Driving with cannabis in the car: the rules in 21 states

Yes in the 17 adult-use states, if you are 21 or older, keep to the state's limit and store it the way the state requires; in Florida, Pennsylvania, Oklahoma and Texas, only patients or caregivers registered or licensed by that state may. California's Department of Cannabis Control says cannabis in a vehicle must stay in a sealed package or container, or else ride in the trunk.

New York's regulator says it is legal for adults 21 and older to possess cannabis in a vehicle and that it should always be securely stored in a closed container. Drivers and passengers may each carry up to the state possession limits: 3 oz of cannabis and 24 g of concentrate.

The amount you may have in the car is the state's possession limit. Arizona and Washington allow 1 oz of flower: Arizona counts up to 5 g of concentrate inside that ounce, and Washington allows 7 g of concentrate besides (A.R.S. 36-2852; RCW 69.50.4013). California's limit is 28.5 g, plus 8 g of concentrate (Health and Safety Code 11362.1), Maryland's 1.5 oz of usable cannabis, 12 g of concentrate or other products with a total of 750 mg of THC (Md. Code, Criminal Law 5-101), and Connecticut's 1.5 oz (Conn. Gen. Stat. 21a-279a). New Jersey's personal-use protection covers 1 oz bought from a licensed store; up to 6 oz draws no penalty, but the Attorney General tells police that anything above 1 oz may be seized (N.J.S.A. 2C:35-10a, 2C:35-10). Massachusetts, New Mexico and Minnesota allow 2 oz, as does Oregon in a public place (M.G.L. c. 94G, s. 7, as rewritten by St. 2026, c. 65; NMSA 26-2C-25; Minn. Stat. 342.09; ORS 475C.337), and Colorado dropped the state offense for holding up to 2 oz in House Bill 21-1090. Nevada, Michigan and Ohio allow 2.5 oz (NRS 678D.200; MCL 333.27955; R.C. 3796.221), and Missouri 3 oz, the same as New York (Missouri Constitution, Article XIV, Section 2.10).

Illinois is the one adult-use state here that sets a lower carry limit for visitors: products with 500 mg of THC, 5 g of concentrate and 30 g of flower, half what a resident may hold (410 ILCS 705/10-10, as amended by Public Act 104-463). Ohio's protection reaches only marijuana bought from a dispensary licensed in Ohio or home-grown under its law (R.C. 3796.221, 3796.04), so a bag bought in another state has none on an Ohio road. The state-by-state storage rules are in the section on where the cannabis must ride.

It depends on the state, and in about half of them the answer is no. Nine of the 17 adult-use states restrict opened cannabis in the cabin: California, New York, Colorado, New Jersey, Illinois, Massachusetts, Washington, Ohio and Minnesota. In California, the regulator calls an open container illegal while you drive or ride in a vehicle, and Health and Safety Code 11362.3(a)(4) forbids an open container or package for anyone driving or operating a vehicle or sitting in its passenger seat.

New York's regulator says open containers of cannabis are illegal in a vehicle, and that neither drivers nor passengers can open any cannabis packaging while in a vehicle.

Purchases leave California stores in an opaque exit package, and cannabis packages there must be tamper-evident, so keep the product sealed until you reach where you are staying (4 CCR 15413(b)-(c)).

Connecticut regulates where larger amounts ride rather than open packages, and the laws cited in this guide for the other seven adult-use states, Nevada, Arizona, Michigan, Maryland, Oregon, Missouri and New Mexico, set no open-package rule for adult-use buyers. That is not permission to open a package on the road: drivers in all of them but Missouri are barred from using cannabis at the wheel, as the section on passengers explains.

The penalty for an opened package ranges from a traffic ticket to a misdemeanor. California treats it as an infraction carrying up to $100 under Vehicle Code 23222(b), or up to $250 under Health and Safety Code 11362.4(b), Washington as a traffic infraction whose base penalty may not exceed $250 (RCW 46.61.745, 46.63.110), and New Jersey fines $200 the first time, then $250 or 10 days of community service (N.J.S.A. 39:4-51b). Massachusetts can impose a civil penalty as high as $500 under M.G.L. c. 94G, s. 13(d), Ohio charges a minor misdemeanor for each violation (R.C. 3796.062, 3796.99(I)), and in Minnesota it is a misdemeanor, which can mean a $1,000 fine and 90 days in jail (Minn. Stat. 169A.36, 609.03). Illinois charges a Class A misdemeanor, with jail of less than a year and fines up to $2,500 possible (625 ILCS 5/11-502.15 and 730 ILCS 5/5-4.5-55).

Most of the storage rules below leave two choices: keep the package sealed, or put it where no one in the car can reach it. California accepts a sealed package or container, or the trunk (Health and Safety Code 11362.3; Vehicle Code 23222). Washington, Ohio and Minnesota accept an unopened package anywhere and an opened one in the trunk or, in a car without a trunk, a space the driver and passengers do not normally occupy; Washington and Minnesota both count a glove compartment as occupied space, so it does not qualify (RCW 46.61.745; R.C. 3796.062; Minn. Stat. 169A.36). Ohio sends homegrown cannabis to the trunk, or that substitute space, even when it is unopened (R.C. 3796.062(C)).

Three more states word the rule their own way. In New Jersey, unsealed cannabis meant for smoking, vaping or aerosolizing belongs in the trunk; a vehicle with no trunk can use the space behind its last upright seat, and a motor home its living quarters (N.J.S.A. 39:4-51b). Massachusetts bans open containers only in the passenger area, which leaves the trunk, a locked glove compartment, a motor home's living quarters and, without a trunk, the area behind the last upright seat (M.G.L. c. 94G, s. 13(d)). Illinois wants the container odor-proof and child-resistant, sealed or resealable and secured, and kept out of reach, though a dispensary purchase still in packaging of that kind may stay within reach (625 ILCS 5/11-502.15; 410 ILCS 705/15-85).

New York, Colorado and Connecticut set narrower rules. New York's regulator wants cannabis in a closed container and bars drivers and passengers from opening packaging in the car. Colorado's open container law treats a package as open only when it is open or unsealed, some of it is gone and there is evidence of use in the car, and it bars such a package anywhere in the passenger area of a car on a public road, glove compartment included, as a class A traffic infraction with a $50 fine (C.R.S. 42-4-1305.5). Connecticut lets 1.5 oz ride anywhere, but a larger amount, up to 5 oz, must be in a locked glove box, or a locked trunk out of reach of the passenger area, of the person's motor vehicle, and the rear cargo space of a hatchback, wagon or SUV is not treated as a trunk (Conn. Gen. Stat. 21a-279a).

Seven adult-use states name no storage spot in the laws cited here. Nevada, Arizona and Michigan set none in their adult-use provisions on driving and possession (NRS 678D.200, 678D.300; A.R.S. 36-2851, 36-2852; MCL 333.27954, 333.27955), Maryland's vehicle statute governs consumption rather than how a sealed product travels (Transportation 21-903), Oregon's Vehicle Code rules of the road contain only the ban on use (ORS 811.482), Missouri's constitution has no open-container provision for marijuana, and New Mexico's Motor Vehicle Code has none. Packaging still matters in some of them: Maryland's Cannabis Administration tells buyers to leave products in the original child-resistant packaging, Missouri's constitution requires every product to be sold in a child-resistant container (Article XIV, Section 2.9(5)), and Michigan's rules require curbside and drive-through orders to be handed over in an opaque bag (Mich. Admin. Code R 420.207a).

The medical-only states have their own packaging rules for patients. Florida and Pennsylvania require patients to keep medical marijuana in its original packaging, and Pennsylvania patients must carry their ID card with it (s. 381.986(14)(a); 35 P.S. 10231.303). In Oklahoma, the medical law bars cities and counties from limiting a licensed patient's right to transport legal amounts (63 O.S. 427.8(B)).

Not in most of the 21 states, although a few statutes reach only smoking or vaping. Under Health and Safety Code 11362.3(a)(7)-(8), no one in California may smoke or ingest cannabis at the wheel, or while riding along as a passenger, unless the vehicle runs under a local on-site consumption permit and no one under 21 is aboard.

New York's regulator says it is illegal for the driver or any passenger to smoke cannabis in a vehicle, moving or parked, and NYC's Health Department says the same applies even when the car is parked.

Seven more states rule out passenger use of any kind in their statutes. Nevada's consumption offense, a misdemeanor that can cost up to $600, makes no distinction between driver and passenger (NRS 678D.310); Arizona's adult-use law gives no one permission to consume marijuana as a passenger in an operating vehicle (A.R.S. 36-2851); and Illinois bars everyone from using cannabis in a motor vehicle (410 ILCS 705/10-35). Washington makes consuming cannabis by any method in a vehicle on a public highway a traffic infraction (RCW 46.61.745), Minnesota bans its use in a motor vehicle by anyone (Minn. Stat. 342.09, subd. 1), and a Connecticut passenger who smokes, inhales or ingests it while someone else drives commits a class D misdemeanor, punishable by 30 days in jail and a $250 fine at most (53a-213b; 53a-36 and 53a-42). Oregon's ban covers passengers too, except in a vehicle operated by a common carrier and used mostly to carry paying passengers (ORS 811.482).

Elsewhere the rule is narrower or rests on guidance. Colorado's open container law bars anyone in the passenger area of a car on a public road from using cannabis, except passengers behind the front seat of a vehicle used mainly to carry people for pay (C.R.S. 42-4-1305.5), and its state cannabis site and transportation department add that the ban holds even when the car is not moving. Maryland's Cannabis Administration calls use by a driver or a passenger illegal, though the state's vehicle statute names only the driver (Transportation 21-903), and New Mexico's Cannabis Control Division says all consumption, eating included, must take place in a private home or a licensed consumption lounge. New Jersey's passenger rule covers only smoking, vaping and aerosolizing while the car is in operation (N.J.S.A. 39:4-51a), Michigan's adult-use law does not authorize smoking in a vehicle's passenger area on a public way (MCL 333.27954), and Ohio treats smoking or vaping by a passenger while the driver operates the car as a third-degree misdemeanor, punishable by as much as 60 days and $500 (R.C. 3796.99(A); 2929.24 and 2929.28). Massachusetts reaches passengers through its open container rule, since a package may not be opened anywhere in the passenger area under M.G.L. c. 94G, s. 13(d).

Missouri's constitution names smoking in a moving vehicle only as something other laws may ban (Article XIV, Section 2.3(1)(f)), and Oklahoma's smoking law bars smoking or vaping marijuana aboard any vehicle that provides public transportation (63 O.S. 1-1523). Florida, Pennsylvania and Texas are covered in the medical-only section below.

You can carry cannabis within the state possession limit in the 17 adult-use states, but in most of them passengers may not use it in a car, taxi or rideshare. In California the passenger ban covers eating it too, on any vehicle used for transportation, and smoking it on public transit is illegal in California and New York.

California lets adults 21 and older possess and transport up to 28.5 grams of cannabis and 8 grams of concentrated cannabis (Health and Safety Code 11362.1), and HSC 11362.3(a)(4) bars an open container or package while riding in the passenger seat or compartment of a motor vehicle, boat, aircraft or "other vehicle used for transportation." Vehicle Code 23221(b) bars a passenger from smoking or ingesting cannabis in a motor vehicle being driven on a highway, a term the Vehicle Code defines to include streets (VC 360). HSC 11362.3(a)(8) also does not permit smoking or ingesting cannabis while riding in the passenger seat or compartment of a "motor vehicle, boat, vessel, aircraft, or other vehicle used for transportation," except in one operated under Business and Professions Code 26200 with no one under 21 present, and HSC 118925 makes it unlawful to smoke any plant product other than tobacco on a public transportation system.

New York lets adults 21 and older possess and transport up to 3 ounces of cannabis and 24 grams of concentrated cannabis (Penal Law 222.05(1)). In a car, taxi or rideshare on a public road, consuming cannabis is a traffic infraction for the driver or any passenger (Vehicle and Traffic Law 1227 and 134), and Public Health Law 1399-o bans smoking, which PHL 1399-n defines to include burning cannabis, on subways, in underground subway stations, and in buses, vans, taxicabs and limousines carrying passengers. NYC Transit's own rules bar smoking or vaping anywhere on its property, including outdoor stations, and Uber says drug use is never allowed while using its platform.

A rideshare or rental car is simply a motor vehicle, so the passenger rules in the section above apply inside it. Several states also name taxis, buses or public transit in their smoke-free or cannabis laws. Massachusetts counts a taxi as a public transportation conveyance where smoking is banned (M.G.L. c. 270, s. 22), Minnesota's Clean Indoor Air Act classes taxis, limousines and other vehicles for hire as public transportation (Minn. Stat. 144.413, 144.414), New Mexico bans smoking and vaping, cannabis included, on buses and in taxicabs (NMSA 24-16-3 and 24-16-4), and Pennsylvania's Clean Indoor Air Act lists taxicabs, limousines and buses as public places (Act 27 of 2008, section 2). Oklahoma keeps marijuana smoke and vapor out of every vehicle that provides public transportation (63 O.S. 1-1523), New Jersey's cannabis law counts public transit vehicles as public places, where smoking cannabis is not allowed (N.J.S.A. 24:6I-33), and Washington treats public conveyances as public places, where consuming cannabis is a civil infraction (RCW 66.04.010, 69.50.445).

Ohio's smoke-free law lists vehicles among places of employment, which brings a taxi or rideshare under it (R.C. 3794.01), Maryland's Cannabis Administration names taxicabs and limousines among the public transportation where cannabis may not be smoked, and Florida leaves use on any form of public transportation outside protected medical use unless it is low-THC cannabis in a form other than smoking (s. 381.986(1)(k)5). Chicago adds a city fine of $50 for a first offense of using cannabis in any motor vehicle (Municipal Code 7-24-099). Company policies and each transit agency's code of conduct are in our Amtrak, rental car and rideshare guide.

Expect a sobriety test and a charge under the state's impaired-driving law, which in all 21 states covered here reaches cannabis as well as alcohol. California's cannabis regulator says officers may stop a driver they suspect of cannabis impairment and give a sobriety test, whether the vehicle is a car, a boat or something else.

California's public-health department says drug-impaired driving carries the same penalties as alcohol-impaired driving, and the state's SB 540 brochure says penalties for driving high are the same as driving drunk.

New York's regulator says that if you drive under the influence of cannabis, you will get a DUI, and advises anyone unsure whether they are impaired to stay put.

A medical card or a lawful purchase does not excuse impaired driving. Nevada, Arizona and Washington state in their DUI laws that a legal right to use the drug does not defend the charge (NRS 484C.110; A.R.S. 28-1381; RCW 46.61.502), Illinois and Oklahoma say the same of lawful use (625 ILCS 5/11-501; 47 O.S. 11-902(B)), and Maryland allows that defense only to a driver who did not know the drug would impair (Transportation 21-902). Colorado's transportation department says a medical card is no defense, New Mexico's medical law shields no one from prosecution for driving under the influence of cannabis (NMSA 26-2B-5(A)), Florida's patient protections do not cover impairment or a required test (s. 381.986(14)(g)), and Pennsylvania's Medical Marijuana Act and Texas's patient exemption contain no driving exception (75 Pa.C.S. 3802(d)(1); Health and Safety Code 481.111(e)).

Several states spell out how officers test for drug impairment. New Jersey police may call in Drug Recognition Experts, according to its Cannabis Regulatory Commission, Connecticut's DUI statute provides for evaluations by certified drug recognition experts (14-227a), Illinois lets officers use standardized field sobriety tests and validated roadside chemical tests when cannabis is suspected (625 ILCS 5/11-501.2), and Maryland's administration says impairment seen in standardized field sobriety tests is enough for a cannabis DUI arrest. The section on first-offense penalties lists what a conviction carries in each state.

It depends on the state, and several set a jail minimum even for a first conviction. Arizona requires at least 10 consecutive days, though a judge may suspend all but one if the driver completes court-ordered screening, education or treatment (A.R.S. 28-1381), and Oklahoma sets 10 days to a year (47 O.S. 11-902(C)). Pennsylvania's controlled substance subsection and Texas each require at least 72 hours (75 Pa.C.S. 3804(c); Penal Code 49.04), Ohio three consecutive days or a three-day driver intervention program (R.C. 4511.19(G)), and Connecticut 48 consecutive hours unless the sentence is fully suspended in favor of 100 hours of community service (14-227a(g)). Nevada sets 2 days or 48 to 96 hours of community service (NRS 484C.400), and Washington 24 consecutive hours, though the court may substitute electronic home monitoring or 24/7 sobriety monitoring (RCW 46.61.5055).

Other states cap the jail term without setting a floor. Michigan allows up to 93 days and a $100 to $500 fine (MCL 257.625), Maryland up to 2 months and $500 for driving impaired by a drug (Transportation 21-902), and New Mexico up to 90 days and $500, plus community service, DWI school and an ignition interlock (66-8-102). Minnesota's base fourth-degree DWI is a misdemeanor, which carries up to 90 days and $1,000 (Minn. Stat. 169A.27, 609.03), Missouri classes a first DWI as a class B misdemeanor, which carries as much as six months and $1,000 (RSMo 577.010, 558.011, 558.002), and Florida's first DUI up to 6 months and a $500 to $1,000 fine (s. 316.193). Illinois treats a first DUI as a Class A misdemeanor, which allows less than a year in jail and fines up to $2,500 (625 ILCS 5/11-501 and 730 ILCS 5/5-4.5-55), and Massachusetts allows up to two and a half years, a $500 to $5,000 fine or both (M.G.L. c. 90, s. 24).

License penalties and fines are added to any jail term. New Jersey's commission lists a license loss of 7 months to a year, a $300 to $500 fine, up to 30 days in jail and a 12 to 48 hour program at an Intoxicated Driver Resource Center for a first offense, and New York's DMV lists a $500 to $1,000 fine, up to a year in jail and a revocation of at least six months for a first DWAI-Drug conviction. Ohio adds a license suspension of one to three years and a $565 to $1,075 fine (R.C. 4511.19(G)), and Connecticut a 45-day suspension, then 12 months in which the driver may use only a car fitted with an ignition interlock (14-227a(g)).

Oregon's fine for a first DUII is at least $1,000 when no prison term is imposed (ORS 813.010), Washington sets $350 to $5,000 (RCW 46.61.5055), Arizona at least $250 plus two assessments of $500 each (A.R.S. 28-1381), Pennsylvania $1,000 to $5,000 (75 Pa.C.S. 3804(c)), and Nevada $400 to $1,000 (NRS 484C.400). Colorado fines a first DUI $600 to $1,000 and a first conviction for driving while ability impaired $200 to $500, with jail of 5 days to a year or 2 to 180 days whose minimums a court may suspend after an alcohol and drug program (C.R.S. 42-4-1307(3), (4)), and California's public-health department says only that the penalties for drug-impaired driving match those for driving drunk. A Massachusetts conviction also revokes the license for a year unless the driver is eligible for, and takes, the first-offender option under section 24D, with a hardship hearing possible after three months (M.G.L. c. 90, s. 24).

Not in most of the 21 states. Thirteen set no THC figure for drivers at all: California, New York, New Jersey, Arizona, Massachusetts, Maryland, Oregon, Connecticut, Missouri, New Mexico, Minnesota, Florida and Texas; New Jersey's DUI law asks only whether the driver was under the influence of a narcotic, hallucinogenic or habit-producing drug (N.J.S.A. 39:4-50(a)). In those states a conviction turns on whether the driver was impaired by, or under the influence of, a drug, cannabis included. Washington, Illinois and Ohio set per se blood levels, Nevada and Colorado use numbers in narrower ways, and Oklahoma and Pennsylvania treat any amount as enough for a DUI.

In California and New York the alcohol limit is 0.08 percent or more by weight in the blood (Vehicle Code 23152(b); Vehicle and Traffic Law 1192(2)). California's drug clause, VC 23152(f), bars driving while under the influence of any drug, and VC 312 defines a drug by its effect, as any substance besides alcohol that could impair driving to an appreciable degree. New York's VTL 1192(4) bars driving while a drug impairs your ability, VTL 114-a counts cannabis and concentrated cannabis as drugs, and the drug provisions of the two codes set no blood level.

In a January 2021 report to the Legislature, a California Highway Patrol task force recommended that a per se limit for drugs other than alcohol not be enacted at this time, saying current scientific research does not support one. New York's cannabis regulator gives the practical version: "If you feel different, you drive different."

The three per se states measure it differently. Washington's line is a THC concentration of 5.00 or more, counted as nanograms of delta-9 THC per milliliter (ng/mL) of whole blood, shown by a blood test within two hours after driving; the metabolite carboxy-THC does not count, and a driver under 21 violates the law with any THC above 0.00 (RCW 46.61.502, 46.04.586, 46.61.503). Illinois sets 5 ng/mL of delta-9-THC in whole blood, or 10 ng/mL in another bodily substance, within two hours of driving, but exempts registered medical patients from that number unless they are impaired (625 ILCS 5/11-501, 11-501.2). Ohio's limits are 2 ng/mL of marihuana in whole blood, serum or plasma and 10 ng/mL in urine, with separate figures for the metabolite (R.C. 4511.19(A)(1)(j)). In all three, impairment at any level is also an offense.

Nevada keeps blood thresholds of 2 ng/mL for THC and 5 ng/mL for its metabolite, but they now apply only to felony-level charges, for example a third DUI in seven years, or a DUI that causes death or substantial bodily harm, and marijuana is no longer in the misdemeanor per se table (NRS 484C.110, 484C.400). In Colorado, a blood test showing 5 ng/mL or more of delta-9 THC allows an inference that the driver was under the influence of drugs (C.R.S. 42-4-1301(6)(a)(IV)), and the state's transportation department says officers may still arrest below that level if they see impairment.

Oklahoma and Pennsylvania are zero tolerance. Pennsylvania's DUI law is broken by any amount of a Schedule I drug, or of its metabolite, in a driver's blood, and marijuana is on the state's Schedule I (75 Pa.C.S. 3802(d)(1)); Oklahoma's rule reaches any amount in the blood, saliva, urine or another bodily fluid at the time of a test (47 O.S. 11-902(A)). Michigan's Vehicle Code has a similar clause for schedule 1 substances, a list that includes marijuana (MCL 257.625(8) and 333.7212). In People v Koon (2013), Michigan's Supreme Court kept the clause from reaching registered medical patients who were not impaired, and the adult-use act protects adults 21 and older who internally possess marijuana but not driving under its influence (MCL 333.27955, 333.27954).

Arizona, Missouri and Minnesota address the point in their own laws. Arizona's DUI statute separately bans driving with a listed drug or a metabolite of one in the body, yet its adult-use law counts marijuana metabolites only when the driver is impaired to the slightest degree as well (A.R.S. 36-2852 and 28-1381). Missouri's constitution demands proof that a driver aged 21 or over was actually under the influence, so THC or its metabolites in the body are not enough (Article XIV, Section 2.3(1)(d)), and Minnesota's DWI law exempts cannabis from the provision that makes the presence of any Schedule I or II drug a violation (Minn. Stat. 169A.20, subd. 1).

Officers can investigate impaired driving everywhere, but lawful cannabis alone is not grounds for a search or arrest in California or New York, and several other states limit what its smell can justify. If you are arrested for impaired driving in California or New York, the law treats you as having already agreed to chemical testing, and a refusal brings penalties of its own.

California's Health and Safety Code 11362.1(c) says cannabis involved in lawful conduct is not contraband or subject to seizure, and that lawful conduct cannot be the basis for detention, search or arrest, but HSC 11362.3(a)(4) says that protection does not cover possessing an open container or open package while driving, operating, or riding in the passenger seat or compartment of a vehicle. A driver lawfully arrested for DUI is deemed to have consented to a blood test for drug content (Vehicle Code 23612(a)(1)(B)). Refusing leads to a one-year administrative suspension of the privilege to drive, or a two- or three-year administrative revocation if the refusal comes within 10 years of prior DUI-related violations, and the refusal may be used against you in court (VC 23612(a)(1)(D) and (a)(4)).

Under New York's Penal Law 222.05(3), a finding of reasonable cause cannot be based solely on the odor of cannabis, the odor of burnt cannabis, or possession of a legal amount. Under 222.05(4), the burnt-cannabis part of that rule does not apply when an officer is investigating whether a driver is impaired by drugs, although during such an investigation "the odor of burnt cannabis shall not provide probable cause to search any area of a vehicle that is not readily accessible to the driver and reasonably likely to contain evidence relevant to the driver's condition." Anyone who drives in New York is deemed to have consented to a chemical test of breath, blood, urine or saliva for alcohol or drug content (Vehicle and Traffic Law 1194(2)(a)); a license revoked after a refusal cannot be restored for at least one year, and the refusal can be used at trial if you were warned in clear and unequivocal language of the effect of refusing and still refused (VTL 1194(2)(d) and (f)).

The smell rule varies. Under Arizona law the smell of marijuana, by itself, does not create reasonable suspicion of a crime outside a DUI investigation (A.R.S. 36-2852), and Missouri's constitution says the same, with an exception for investigations of impaired driving or boating (Article XIV, Section 2.10(10)). New Mexico says odor alone is not grounds to stop or search, except when an officer is investigating drunk or impaired driving (NMSA 26-2C-25(C), (D)), and New Jersey's Attorney General has told officers that the odor of raw or burnt marijuana is not, on its own, a reason to prolong a stop or to search for a possession case, unless probable cause of impaired driving develops. Since 1 Oct 2025, Connecticut police may stop a car for cannabis use alone only if an officer both sees the driver consuming it and detects the smell of burnt cannabis (Public Act 25-19).

Testing laws differ. Nevada treats every driver as consenting to a breath, blood, urine or other bodily substance test once an officer has reasonable grounds, and requires the officer to warn that a refusal means license revocation (NRS 484C.160). Colorado's transportation department says anyone arrested for suspected DUI must submit to chemical testing, Texas deems an arrested driver to have consented to breath or blood tests (Transportation Code 724.011), and Oregon deems a DUII arrestee to consent to a urine test for drugs if the breath result is below 0.08 percent, or if a crash injured someone or damaged property (ORS 813.131).

Refusing carries its own consequences in many states. In Florida a first refusal of a urine test suspends driving privileges for a year, is a second-degree misdemeanor and can be used in court (s. 316.1932(1)(a)1.b). Minnesota makes refusing a chemical test a crime of its own (Minn. Stat. 169A.20, subd. 2), in New Mexico a refusal makes the case aggravated DWI if the court finds the driver impaired, and a first aggravated conviction carries 48 consecutive hours in jail or more (66-8-102(D) and (E)), and in Washington a refusal raises the first-offense minimums to 48 hours and $500 (RCW 46.61.5055). Illinois admits a refusal to take roadside cannabis tests as evidence (625 ILCS 5/11-501.2).

Because the effect can be delayed, and driving under the influence is illegal. New York's regulator says an edible can take as long as four hours to take effect and to stay put if you are not sure whether you are impaired; California's cannabis regulator says edibles can take up to two hours to begin working and up to four hours for full effects.

The edibles basics guide explains the official onset and duration figures in full.

Regulators in other states give similar timings. Nevada's says eaten or drunk cannabis may take two hours to reach its peak, New Jersey's and Minnesota's put the onset of an edible at 30 minutes to 2 hours, and New Jersey's warns that driving impairment can last several hours. Illinois's oversight office says the full effect often arrives only after 2 to 4 hours, and Massachusetts's 2018 consumer notice warned of delays of two hours or more. Maryland's administration suggests waiting six hours after use before driving, and longer after an edible, since edible effects may last as long as 12 hours, and Colorado's state site suggests that occasional users wait eight hours or more before driving after eating or drinking as much as 18 mg of THC.

Largely, yes, though the boat and aircraft rules below cover only some of the 21 states. In California and New York a motorcycle is a motor vehicle and operating a vessel while impaired by drugs is illegal (in New York, a motor-powered one), and California's open-container and no-use rules name boats and aircraft alongside cars.

California's Health and Safety Code 11362.3 bars an open container or package of cannabis while driving, operating or riding in a "motor vehicle, boat, vessel, aircraft, or other vehicle used for transportation," and bars smoking or ingesting it while driving or operating one. Vehicle Code 400 defines a motorcycle as a motor vehicle, and VC 23152(f) makes it unlawful for a person under the influence of any drug to drive a vehicle. Harbors and Navigation Code 655(b) bars operating any vessel, or using water skis or a similar device, while under the influence of any drug.

In New York, Vehicle and Traffic Law 123 defines a motorcycle as a motor vehicle, so the drugged-driving ban in VTL 1192(4) covers motorcyclists. Navigation Law 49-a(2)(e) bars operating a motor-powered vessel while your ability is impaired by a drug as defined in VTL 114-a, which includes cannabis. For airports and flights, see our guide to flying with cannabis.

Several other states name boats or aircraft directly. Arizona's adult-use law gives no permission to consume marijuana while operating or riding in an operating boat, vessel or aircraft, and does not allow boating or flying while impaired to even the slightest degree (A.R.S. 36-2851). Michigan's does not authorize operating an aircraft, snowmobile, off-road vehicle or motorboat under the influence of marijuana, or consuming it while doing so (MCL 333.27954). Missouri's constitution leaves in force laws against operating a train, aircraft or motorboat under the influence (Article XIV, Section 2.3(1)), and a first offense of boating while intoxicated is a class B misdemeanor (RSMo 577.013).

Maryland makes it an offense to run a vessel when any drug has left you unable to operate it safely (Natural Resources 8-738), and a first offense can mean a $500 fine, 2 months in jail or both. Florida treats operating a vessel while impaired by a controlled substance as boating under the influence, and a registered patient may not use marijuana in a boat (s. 327.35; s. 381.986(12)(c)). Ohio's watercraft law has its own marihuana thresholds (R.C. 1547.11). On any waters subject to U.S. jurisdiction, a federal standard that the Coast Guard enforces also applies: an operator is under the influence when an intoxicant's effect on manner, speech, muscular movement, appearance or behavior is apparent by observation, and the definitions cover every controlled substance on Schedules I to V (33 CFR 95.005, 95.010, 95.020).

The first question for a visitor is whether marijuana may be in the car at all, and usually it may not. Florida, Pennsylvania and Texas serve only their own registered patients and accept no other state's card, so a visitor's marijuana is a possession offense in a car as anywhere else (Fla. Stat. 381.986; 35 P.S. 10231.303; Occupations Code 169.003). In Florida, holding up to 20 g of plant cannabis counts as a first-degree misdemeanor, and a third-degree felony applies to any resin-based product, whatever the weight, which takes in concentrates, most vape oil and edibles infused with extract, unless the product qualifies as hemp (s. 893.13(6)). Pennsylvania charges a misdemeanor even for 30 g or less (35 P.S. 780-113). Texas charges a Class B misdemeanor for 2 oz or less (Health and Safety Code 481.121), and a THC vape, oil or edible from another state's dispensary that weighs under a gram is a state jail felony (481.116; Penal Code 12.35).

Oklahoma is the exception for visitors who already hold a card. A holder of a government-issued medical license from another state's program may apply to the Oklahoma Medical Marijuana Authority (OMMA) for a temporary license good for 30 days, and a licensed patient may carry up to 3 oz on their person and transport it within the legal limits (63 O.S. 420(A), (F), 427.8(B)). Anyone without that license commits a misdemeanor with any amount, punishable by as much as a $1,000 fine and a year in confinement; a person holding 1.5 oz or less who can state a medical condition is instead cited and fined no more than $400 (63 O.S. 2-402 and 420(B)).

Registered patients have car rules of their own. A Florida patient who uses marijuana inside a vehicle or on a boat is guilty of a first-degree misdemeanor, the one exception being low-THC cannabis used in a form other than smoking (s. 381.986(1)(k)5, (12)(c)), and SB 1056, a 2026 bill that would have created an open-container offense for marijuana products, died in committee. Smoking medical marijuana is unlawful everywhere in Pennsylvania, for patients too (35 P.S. 10231.304), and Oklahoma bans smoking or vaping it on any vehicle that provides public transportation (63 O.S. 1-1523). In Texas, the Department of Public Safety says dispensed products carry labels that help officers confirm the prescription.

The impaired-driving rules apply to patients in all four. Oklahoma and Pennsylvania count any marijuana or metabolite in the driver's body as DUI, and Oklahoma requires every dispensary label to carry a warning that it is illegal to drive under the influence of marijuana (63 O.S. 427.18). Florida's DUI test is impairment of normal faculties, and Texas's is the loss of normal use of mental or physical faculties (s. 316.193(1)(a); Penal Code 49.01). A Florida conviction for possessing a controlled substance also brings a court-ordered loss of the license or driving privilege for 6 months, or until a required treatment program is done (s. 322.055(1)), and from 1 Nov 2026 Oklahoma lists hemp-derived THC in Schedule I, which brings it under the any-amount DUI rule (47 O.S. 11-902(A)(3); SB 1257).

Not legally. Official sources in 14 of the 21 states say cannabis may not cross a state line, among them California's regulator, which says you cannot take it across, and New York's, which calls crossing with cannabis, medical cannabis included, illegal.

California even bars its own licensed delivery drivers from leaving the state while carrying cannabis goods (4 CCR 15416(b)). Adult-use cannabis also remains a Schedule I controlled substance under federal law (Federal Register 2026-08176).

The other twelve are Colorado, whose state cannabis site calls taking any cannabis product out of Colorado illegal; New Jersey's Cannabis Regulatory Commission; Illinois's Cannabis Regulation Oversight Office; Massachusetts's Cannabis Control Commission, which names cars, planes, trains and boats; Ohio's Division of Cannabis Control; Washington's Liquor and Cannabis Board, even when the destination allows cannabis; Maryland's Cannabis Administration; Oregon's Liquor and Cannabis Commission; Connecticut's Department of Consumer Protection; Minnesota's Office of Cannabis Management; New Mexico's Cannabis Control Division; and Oklahoma's Medical Marijuana Authority, which bars its licensed patients from leaving the state with medical marijuana.

For Nevada, Arizona, Michigan, Missouri, Florida, Pennsylvania and Texas, the sources cited here carry no such statement, but each state's protection still ends at its border; Nevada's law, for one, exempts adults only from prosecution by Nevada (NRS 678D.200). Ohio adds a rule for the drive in: it bars carrying any marijuana in a motor vehicle other than adult-use, medical or homegrown marijuana as its own law defines them, and it protects adult-use marijuana only when it was obtained from a dispensary licensed in Ohio, so a purchase from Michigan has no protection on an Ohio road (R.C. 3796.062(A), 3796.01(A)(9), 3796.221(A)). Pennsylvania's zero-tolerance DUI rule turns on what is in the driver's blood, not where the cannabis was bought (75 Pa.C.S. 3802(d)(1)), and on the highways leading north out of the Big Bend area, Border Patrol checkpoints stop every northbound vehicle, where federal possession law applies (21 U.S.C. 844).