Elinda wrote:
Take a look at the study I linked about 4 posts up. Research at the University of Utah used driving simulators to measure reaction times on different driving tasks. The variables were driving with no conversation, driving with a friend sitting next to you and chatting, and driving while conversing over a phone.
Yup. That's one of the tests which I was talking about earlier. They constructed a test designed to maximize the amount of distraction a cell phone conversation might generate and should not be surprised at all that they saw it reflected in the data. They programmed the simulator to require that the driver make regular lane changes, and instructed the partners to engage in a specific conversation style designed to maximize the amount of participation the driver would have to engage in. They also allowed conversation with a passenger to drift into a talk about the drive itself. Which, while reasonable in "real" driving conditions, is unfair given that they set the simulator to prevent what a cell phone user would do under similarly "real" driving conditions (stay in one lane while talking on the phone).
They made note of the frequency with which conversation drifted, but if all you do is look at the tables, you won't realize this factor, or how important it is. This study obtained different results than most. Usually, the driver talking on the cell phone slowed down. In their tests, the drivers sped up. Presumably, they realized that the constraints of the test (active conversation while actively driving) was difficult and attempted to end the task as quickly as possible. In a real situation, the driver would either slow down and stay in one lane, or end the call if the conditions got a bit too tricky.
This test is a particularly bad one exactly because they made it impossible for the driver talking on the cell phone to reduce the degree of distraction caused by the conversation, but allowed exactly that to occur when they were talking with a passenger. If the objective is simply to determine that increased distraction will reduce driving capacity, they succeeded. But then, we already knew that. If they wanted to test if just having a conversation on a cell phone is inherently more dangerous than having a conversation with someone in the car, they should have enforced the same rules for both. They didn't.
They're also putting drivers in a simulator (which they're not familiar with), and under contrived driving conditions. Under those circumstances any physical activity will cause impairment. If they'd instructed the driver to change the radio station at least once every 30 seconds, they'd have gotten similarly skewed results. Put the same drivers in their own cars, give them an objective, but don't contrive the conditions. Allow the driver to adjust his driving to his current state of distraction. Just as you don't choose to fiddle with the radio right as you're passing between two semis, you adjust your conversation from listening to talking based on traffic conditions. They allowed this to occur when a passenger was in the car, but did not when they were on the phone. While this was meant to simulate the assumption that a passenger would modify his conversation to the driving conditions, but someone on the other end of a cell phone would not, that assumption skews their results. They should have simply instructed the driver to carry on a conversation as he saw fit, just as he would do if he were actually driving and talking in a real world situation.
It's a badly flawed study. Unfortunately, that's what seems to pass for studies in most universities these days. They start with an assumption, then contrive a test to show that their assumption happens. I can almost imagine the professor asking his students: "Ok. So, what conditions could we set which would most highlight the distraction talking on a cell phone would create...". That's the wrong way to approach such tests. You're biasing the results before you even start.
Quote:
It pretty much supports what Sami says.
Of course. She linked to an article which was written about the exact same study. What you'll find is that a whole lot of articles out there refer to just a handful of actual studies that have been done. And not one of them actually test real drivers in relatively real situations and allow them to moderate their own behavior based on driving conditions (which every driver would do).
If I require that you must light your cigarette whilst driving 100 mph on a one lane highway, I'll be able to show that lighting a cigarette is incredibly dangerous. Of course, if I allow you to adjust your speed to something that is safe while lighting said cigarette, the numbers will change, wont they? That's why the Utah study is flawed. That's why most of the studies are flawed. I haven't found one yet that really tested hands-free cell phone use against normal driving that didn't place similar requirements on the driver while talking on the cell phone.
The Utah study is actually one of the worst offenders. If you wanted to pick an example, there are better ones.
Not actually interested so much in distraction, as with the idea that we use different parts of our brain depending on whether we have people with us on hidden from us.