Why would it bother OCR'ing road signs? That seems much more error prone and needlessly complex. That data is readily available from a data sources based on your GPS location, I know TomToms and other navigation devices have it.
The latest models also detect pedestrians, bikes, and even animals -- and the car sets off an alarm and brakes so that we don't run over them. High beams are politely turned off when meeting another car, as well as when passing near pedestrians. The software also performs lane detection, shows you where you're heading when moving in reverse, signals to the driver when another vehicle is close by to the left or right, even if you can't seen them in the rearview mirrors.
Volvo has a goal of preventing or mitigating accidents to such an extent that by 2020 nobody will die in a Volvo when there is a car accident. Their commitment to the safety of car passengers was such that they let everyone freely use their patented seat-belt system when they improved it. They've been running a team in Sweden for decades that travels to every single car accident involving a Volvo, so that they can understand the causes and consequences of the accident, sometimes even repeat the event in lab conditions -- and they can improve the cars accordingly.
Yes, we own a (new) Volvo -- we picked it up at the factory in Sweden, drove around Europe for a few weeks, and returned it for them to ship it over to our US address.
There are a lot of other variables to optimize for, both on individual basis (fuel, travel time, battery life, ...) and collective basis (congestion locallity, total time lost in congestion, emissions, ...)
I guess legislatures - over time - will try to optimize some variables for 'the greater good' instead of minimizing your travel time :-)
It's sad that asking questions is considered bad.
I'm not sure what you mean with the other option ?
This functionality is demonstrated in one of the more recent ridealongs of Google's car.
[1] http://commons.wikimedia.org/wiki/File:VBA_showing_100_kilom...
It also covers the (admittedly limited) situations where no GPS is available (tunnels, skyscrapers). If there are temporary changes in speed limits due to construction or other events, OCR could immediately identify those with no need to download new information.