I have to agree that the "onramp to offramp" is BS. The Model S Autopilot won't, on it's own, transition from one freeway to another. It will simply do what the Infiniti Q50 does today (and has done for a couple of years now), and track it's lane.
If this is illegal, almost every car company (and several major auto parts companies) are going to have some big issues. Doesn't seem likely to me.
Elon said they were testing driving from San Francisco to Seattle without the driver touching the steering wheel. I'm almost positive it can't do this if all it does is lane keeping. I-5 up to Seattle splits into multiple roads on several occasions. At a minimum it'd have to be able to put itself into the correct lanes without driver intervention. Does that fall outside the law in some states?
According to this site there are 4 states with laws on Automated Driving:
Automated Driving: Legislative and Regulatory Action - CyberWiki
Nevada
Law is here:
NRS: CHAPTER 482A - AUTONOMOUS VEHICLES
Tesla is probably ok because it seems to be based on the intent of the manufacturer to build a technology that doesn't require monitoring of a human operator. Yes the rules on testing an autonomous vehicle in Nevada require a human operator be monitoring the vehicle, but it seems to only cover vehicles that are ultimately intended to be level 4 vehicles as defined above.
NRS 482A.025 “Autonomous technology” defined. “Autonomous technology” means technology which is installed on a motor vehicle and which has the capability to drive the motor vehicle without the active control or monitoring of a human operator. The term does not include an active safety system or a system for driver assistance, including, without limitation, a system to provide electronic blind spot detection, crash avoidance, emergency braking, parking assistance, adaptive cruise control, lane keeping assistance, lane departure warning, or traffic jam and queuing assistance, unless any such system, alone or in combination with any other system, enables the vehicle on which the system is installed to be driven without the active control or monitoring of a human operator.
California
Law is here (warning PDF):
http://www.dmv.ca.gov/portal/wcm/connect/d48f347b-8815-458e-9df2-5ded9f208e9e/adopted_txt.pdf?MOD=AJPERESCACHEID=d48f347b-8815-458e-9df2-5ded9f208e9e
This one seems to be fuzzier. This one excludes driver assistance just like Nevada, but says that the system can't be capable of driving or operating the vehicle without a human at the controls. I'd say that if Infiniti's implementation doesn't verify the human is there they meet the definition of an "Autonmous vehicle". Tesla may or may not depending on what they end up releasing.
(b) “Autonomous vehicle” means any vehicle equipped with technology that has the capability of operating or driving the vehicle without the active physical control or monitoring of a natural person, whether or not the technology is engaged, excluding vehicles equipped with one or more systems that enhance safety or provide driver assistance but are not capable of driving or operating the vehicle without the active physical control or monitoring of a natural person.
Michigan
Law is here (the public act which is the law as passed):
http://www.legislature.mi.gov/documents/2013-2014/publicact/htm/2013-PA-0231.htm
Which ultimately gets integrated into the Michigan Vehicle Code here:
Michigan Legislature - Act 300 of 1949
Like California it excludes driver assitance systems provided that they can't drive the car without monitoring. Obviously it has the same potential problems for Tesla.
(1) "Automated motor vehicle" means a motor vehicle on which automated technology has been installed, either by a manufacturer of automated technology or an upfitter that enables the motor vehicle to be operated without any control or monitoring by a human operator. Automated motor vehicle does not include a motor vehicle enabled with 1 or more active safety systems or operator assistance systems, including, but not limited to, a system to provide electronic blind spot assistance, crash avoidance, emergency braking, parking assistance, adaptive cruise control, lane-keeping assistance, lane departure warning, or traffic jam and queuing assistance, unless 1 or more of these technologies alone or in combination with other systems enable the vehicle on which the technology is installed to operate without any control or monitoring by an operator.
Florida
Law is here (PDF copy of the enrolled version):
http://www.myfloridahouse.gov/Sections/Documents/loaddoc.aspx?FileName=_h1207er.docx&DocumentType=Bill&BillNumber=1207&Session=2012
Florida Uniform Traffic Control which this is integrated into:
Chapter 316 - 2014 Florida Statutes - The Florida Senate
While the text is similar to California and Michigan it seems that this one is about the intent since it says if the technology is installed to drive. So Tesla is probably safe with this one. But I'd say it still leaves considerable room for interpretation.
(90) AUTONOMOUS VEHICLE.—Any vehicle equipped with autonomous technology. The term “autonomous technology” means technology installed on a motor vehicle that has the capability to drive the vehicle on which the technology is installed without the active control or monitoring by a human operator. The term excludes a motor vehicle enabled with active safety systems or driver assistance systems, including, without limitation, a system to provide electronic blind spot assistance, crash avoidance, emergency braking, parking assistance, adaptive cruise control, lane keep assistance, lane departure warning, or traffic jam and queuing assistant, unless any such system alone or in combination with other systems enables the vehicle on which the technology is installed to drive without the active control or monitoring by a human operator.
Other Laws
Of course none of this accounts for the issues that is brought up in the Wired article. All states could use their reckless driving laws against operators of vehicles with this technology (though they probably won't unless the technology appears to be unsafe). Some states have laws that require the driver always have their hands on the steering wheel (though as many have pointed out that's up to the driver to comply with). I'm sure there are even more laws I haven't bothered to think of that may be impacted by such cars.
Ultimately it comes down to what Tesla implements and how the states interpret their laws. I'm almost certain at some point these vehicles with a combination of driver assistance features that nearly automate driving is going to end up in court over these laws. This all comes down to shades of grey.