would this work?
let the teams use any tires they want but they have to use 2 compounds?
Valencia circuit in a sad state, opportunistic thieves and the homeless taking advantage whilst the track is neglected.
http://www.marca.com/2013/01/23/motor/formula1/1358937864.html
Edit: oops
And a bridge that cost two million now only used by homeless to spend the night.
It wouldn't really work as the teams would work out the best ones to use, so all of them would use the same tyres any way.
The bridge was built for the Americas Cup, not F1.