As well as time dilation slowing the rate that clocks run and things age etc, wouldn’t it also slow the rate of the very speed that was causing the time dilation? Isn’t time dilation effectively speed dilation? In other words, the faster you go the slower you go, and if you could ever reach the speed of light you would stop completely as time stops. As you were constantly increasing your speed to reach the speed of light however, wouldn’t time dilation reduce your ability to constantly increasing your speed, and at a certain point of speed/time dilation couldn’t you only travel at a constant speed? In other words, wouldn’t the maximum speed that a thing could travel be governed by the amount of time dilation that the speed creates? If so, could time dilation be what governs the speed of light?