The joint commission shall sit as may be deemed expedient in order to determine the cost of the properties to be acquired, including the franchise incident thereto, situated in this state and the state of Pennsylvania, and also to determine any compensation to be allowed, as of the time of entry upon and taking possession of the property, for the value of the property, franchises, easements or rights in the two states. The franchise shall be estimated on its present value as incident to the property and not upon estimated future receipts from toll charge.