Driverless cars may be modern and use half of what todays taxis use . Yet they are not truly driverless, they still alert the driver to take over in certain conditions , for example pulling in and out of drive ways or driving through road work or accidents. Which brought them to the idea of embedding streets with an electrical cable that sends radio signals to a reciever on the front and end of the car , which is stated in the passage. These smart road systems worked well but require massive upgrades to existiing roads , which is simply too expensive. So with out the smart roads a whole lot of sensors are needed on the car , one specific sensor is the special touch sensor which makes sure that the driver keeps their hands on the wheel at all times . Besides that there is also seats that viberate to alert the driver and flashing lights on the window shields , which would add on to the price of a car. Also stated in the passage that so far none of the cars are completely driverless. They can steer , accelerate and brake themselves but they still notify the driver when the road ahead requires human skills . This means the human driver must be alert and ready to take over at all time. Which might not always happen , a driver may not always be attentive of the road ahead even with alerts included in the car. Which brings up the case of a drivers, passengers , and pedestrians saftey , and lawmakers know that saftey is best achieved with alert drivers , which is stated in the passage. Traffic laws are written with the assumption that the only safe car has a human driver in control at all times. Infering to why in most states it is illegal even to test computer driven cars. Yet even if traffic laws change , new laws willl be needed in order to cover liability in the case of an accident. If an accident were to occur due to the technology failing , who is to blame the driver or the manufacturer.