I don't think it's china interest to have a road link with India, we can finish all the rail connection from Tibet to Nepal, Pakistan, and eventually Bhutan, using lasha as Hub. China has already road and rail direct connectivy with most continental ASEAN countries, Kunming will a trade Hub to these nations on south and use kashgar as trade hub for central asia nations, and with Tibet rail to link these trade hubs togheter, we can create a trimendious trade world just for China along, why we need to share with India? let them find their own way.
And once we extend the silk road connecting Pakistan to Arabs world in Middle East...then we're laughing.