Memorial Day weekend is about barbecues, friends, family, weekend trips and patriotism. For some people it unfortunately also ends up being about the danger of driving under the influence of alcohol.

In places where Uber is commonly used, you would probably not be incorrect to assume that the rate of DUIs goes down. If you pay attention to the pronouncements of people like Chris Sacca, the billionaire Uber investor and "Shark Tank" guest, you might think the reduction is incontrovertible. In reality, though, it's hard to know just what the real effect of Uber on drunk driving has been because, for all the company's claims on the matter, the available data remains a bit scant.

First, let's be clear: There exists data to support the contention that Uber has reduced drinking and driving in places where studies were conducted:

  • A Temple University study showed a reduction in drinking and driving deaths of between 3.6 and 5.6 percent on weekdays between 2009 to 2014 in California cities that allowed UberX to operate. No impact was found on weekends.
  • In a 2014 post, Uber reported a 10 percent decrease in DUI arrests in Seattle following the company's entry into the market.
  • Based on a report Uber co-authored with Mothers Against Drunk Driving, the company asserted it was responsible for preventing as many as 1,800 drunk driving crashes in California over a roughly three year period starting in 2012.

There also exist issues with each of these pieces of data. The first two points are limited in the impact they demonstrate: The Temple study showed no decrease in DUI deaths on weekends, when the cost of UberX rides tends to rise with demand-based pricing, while the data from Seattle is only from that one city. The MADD study has been the most contentious and was investigated by ProPublica, which quoted a MADD representative as calling the findings "purely correlational."

Uber stands behind the data. The company passed along materials that referred to all three studies when Inc. asked for further materials showing a link between Uber usage and a decline in DUIs. The company said it didn't have further data to share at this time, but noted that highest use times for the service coincide with last call on Friday and Saturday nights in virtually every Uber city globally. But Uber said it would be interested in working with more researchers in the future.

Limited in scope though it may be, the data has inspired unbridled enthusiasm from Sacca. He said at Inc.'s GrowCo conference earlier this month that Uber "has dramatically reduced drunk driving accidents in every city it operates." He said the basically same thing on Twitter recently. "Uber has already been proven to save lives," he tweeted, later continuing that the company's role in reducing DUIs has "been shown again and again."

Sacca continued to express high optimism for Uber's impact on drunk driving in an email to Inc., adding in a statement, "Everyone agrees more studies are needed and welcome. I hope more and more research is done in this space as I am confident the findings will continue to highlight the lives literally saved by Uber."

There simply is not enough hard data to support claims that Uber has a sweeping impact on drunk driving, but nor is there evidence to the contrary. Common sense would say that if you're drunk, you shouldn't drive, and if Uber is your best or easiest option, you should go with it. If your driver has had a decent night's sleep in the past 24 hours, you're likely to get home safer than if you took the wheel yourself.