This won't work. iOS has disk and file encryption, and you cannot access this kind of data without being unlocking. Forcing someone to provide a PIN has been ruled against the first amendment.
Likewise with driving.
It's not the actual manipulation-of-an-automobile part of driving. It's getting around the world in a timely manner, just like everybody else, instead of having to be interned in a bus for an extra hour.
Honest question btw.
Now all that aside, this is quite a stretch ... If the 5th amendment protects you from disclosing a password under a court order, there's no reason you should have to unlock your phone just because a police officer asks you too. Come to think of it, pretty sure that applies that unlocking your trunk either unless the officer has a warrant.
The breathalyzer has the immediacy requirement described elsewhere in this thread, which doesn't apply to your phone. The only reason to avoid getting a warrant is convenience.
Yes, actually, and that question (wrt criminal penalties some states have heaped on) happens to be in front of the Supreme Court right now in Birchfield v. North Dakota[1] (though not for the first amendment, GP is off course there).
Sibling comments are correct on the legal theory behind allowing punishments for refusing to take a breathalyzer test, but it's clearly questionable whether a state should be allowed to issue criminal penalties for availing yourself of your rights. If such a thing were generally allowed, warrants wouldn't be necessary in most cases: let us search your person/phone/car/house/papers without a warrant unless you want severe automatic penalties, etc.
[1] http://www.scotusblog.com/2016/04/argument-analysis-criminal...
Distracted and reckless driving have been laws long before cell phones or laws against drinking while driving. Distracted and reckless driving already carry large fines and are much more subjective with much less burden of proof than finding a text message on a phone.
Instead of the breathalyzer (or other tests for EtOH) we should be testing for ability. I suspect this shouldn't be hard or expensive, for example, to make a portable device that implemented objective tests[1] of ability. Obviously some research would be needed to determine which skills need to be tested and to calibrate the minimum-ability cutoffs.
[1] like this reaction time test: https://faculty.washington.edu/chudler/java/redgreen.html
Isn't that basically how traffic tickets work in general? As far as I understand it, you have the option of rejecting the ticket as long as you're willing to be arrested for the offense instead.
Driving is not a right in any sense, it's a privilege.