Correct. As this link explains:If EVERYONE has a computer in their car to help them avoid traffic jams, then it would be absolutely pointless.
The "Wardrop Equilibrium Principle": Under equilibrium conditions, traffic arranges itself in congested networks in such a way that no individual trip maker can reduce his path costs by switching routes.
If all trip makers perceive costs in the same way then the Wardrop Equilibrium Principle may be re-stated as follows: Under equilibrium conditions traffic arranges itself in congested networks such that all routes between any Origin / Destination pair have equal and minimum costs, while all unused routes have greater or equal costs.
Wardrop's Equilibrium Principle has caused many a graduate student taking a transportation engineering course in network optimization to take up drinking.