If you have ever done the Detroit/Windsor bridge crossing, you know how frustrating it can be.
Because the bridge was built before the interstate ever existed, both ends of the bridge are connected with city streets and not the interstate. This means that to get to and from the interstate to the bridge, you have to drive through the city looking for signs on poles which direct you right, left or straight. And, if you miss a turn, you end up in a very bad neighborhood.
Now, the owner of the existing bridge claims that tolls and traffic are down and that building a new bridge would be a mistake. But, he is willing to spend his own money to add to the existing bridge even thought it is not warranted because traffic is down.
Here is the reality of the situation. If given the choice between crossing on a bridge accessible only by city streets or a bridge connected directly to the interstate, most people will choose the interstate bridge. This means that the existing bridge will no longer be the cash cow for its owner.
Bottom line, the owner of the existing bridge will do all that he can to save his gold mine.