The arbitrator would evaluate the economic value of the development and if it was high enough, tell the hold-outs to yield up possession.
No arbiter is going to force people off their land. At best, he'll specify the value of the land. "I don't want to sell" is a valid statement for any property. In other words, Build around them. Leave them the fuck alone.
Now, you specify that you want to find a solution that ends conflict. Do you really? Or do you want to find a solution that lets you get your way? Let's look at which of our proposed solutions really ends the conflict on the matter.
Your solution:
Group A wants to build a road/railway/whatever through Group B's land. They take a vote, and Group A ends up in the majority. But before construction can begin, Group B gets up a petition, and forces another vote. This time, Group B ends up in the majority. Group A does the same. and so forth. Conflict not resolved, just continued using proxies.
My solution:
Group A wants to build a road/railway/whatever through Group B's land. Group B says no. Group A decides to leave them the fuck alone, and builds around Group B. The road is built, nobody got forced out of their homes, and the conflict is resolved.