Chug coffee to fight sleepiness— it’s hardly a new concept. But a recent study found just one cup of coffee with 80 mg of caffeine could be enough to help drivers stay awake at the wheel.

The study, published in the research journal Psychopharmacology, aimed to establish the effect of just a small amount of coffee on simulated highway drivingEffects of coffee on driving performance during prolonged simulated highway driving. Mets, M.A., Baas, D., van Boven, I., et al. Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands. Psychopharmacology, 2012 Feb 8.. Healthy and non-sleep deprived (nope, the same effects probably wouldn’t be seen after an all-nighter) drivers headed behind the wheel for two hours of boring highway driving before getting a 15-minute coffee break— where half got caffeinated coffee and half got decaf. (Neither the researchers nor the participants knew which kind of coffee they were getting.) Then they were back on the (simulated) road for another two hours, during which their driving was monitored for side-to-side drifting, changes in speed, and their overall driving performance, as well as how tired they said they felt.

Researchers found that in the two hours following the rest stop, caff-ed up drivers drove better, objectively and subjectively. This study’s especially interesting because, in the past, similar studies have found comparable results with much higher quantities of caffeine— even more than twice as muchThe effects of coffee and napping on nighttime highway driving: a randomized trial. Philip, P., Taillard, J., Moore, N., et al. Centre Hospitalier Universitaire de Bordeaux and Université Victor Segalen, Bordeaux, France. Annals of Internal Medicine, 2006 Jun 6;144(11):785-91.. The takeaway? There’s no need to risk the jittery effects of too much caffeine when driving for hours on end. Just one cup (note, not all coffee has the same amount of caffeine) could do the trick, as long as the driver isn’t starting out sleep-deprived. If the body’s tank is running on empty, though, snooze, don’t sip.