Opiates and Benzodiazepines on Driving

Inclusion Criteria: * Healthy adult men and women, based on medical and psychological evaluation * Currently valid unrestricted (except for vision correction) US driver's license * Licensed driver for at least the past two years * Drove at least 5000 miles in the past year, by self-report * Live within a 60 mile radius of NADS * Available for five study sessions, with one being approximately 2 hours and four being approximately 5-6 hours * Peripheral veins suitable for repeated venipuncture * Systolic blood pressure within a clinically normal range (120 ± 30 mmHg) and diastolic blood pressure of 80 ± 20 mmHg * Good command of written and spoken English * Female subjects with reproductive potential must agree to use (and/or have their partner use) one (1) acceptable method of birth control beginning at the screening visit throughout the study (including intervals between treatment periods/panels) and until 2 weeks after the last dose of study drug in the last treatment period. Acceptable methods of birth control include the following: intrauterine device (IUD-with or without local hormone release), diaphragm, spermicides, cervical cap, contraceptive sponge, oral contraceptives or condoms. Abstinence is an alternative lifestyle and subjects practicing abstinence may be included in the study. Exclusion Criteria: * Requires any special equipment to help drive, such as pedal extensions, hand brake or throttle, spinner wheel knobs, or other non-standard equipment * Presence of any clinically significant illness, as detected by history, physical examination, and/or laboratory tests, that might influence driving performance (e.g., seizures, sleep apnea, narcolepsy, vertigo, chronic fatigue syndrome) or put the subject at increased risk of adverse events (e.g., cardiac arrhythmia, hypertension) * If female, pregnant or nursing * Currently taking drugs that are contraindicated for use with study drugs * Significant history of motion sickness or demonstrates significant simulator sickness during practice drives at screening (SSQ). Subjects must have scores below the following values on the SSQ: Nausea \< 21, Oculomotor \<32, Disorientation \< 15, and Total Score \< 32. * History of any illness that, in the opinion of the study investigator, might confound the results of the study or pose an additional risk to the subject from study participation * Prior participation in a driver impairment or distraction-related research study conducted at NADS that uses the same base drive