In a route in progress I have built a dedicated line for a TGV transport between two main cities. I post speed signs and when the train passes the speed limit is indicated on the heads up display. (300km/h signs and 300km/h shown as limit). The AI driver will not get the train up to this speed and obtains a max speed of 165km/h. I have tried various speed signs from 250km/h to 999km/h but the max speed of the AI remains around 165km/h. There is only one TGV on the line with no tie ins and there are no signals on the line. Any suggestions or thoughts?