Trevor was using the cross walk when Mark failed to stop and…

Trevor was using the cross walk when Mark failed to stop and ran over him. Trevor was severely injured. Trevor filed a lawsuit against Mark demanding that he pay him for all his damages because of the accident. Trevor and Mark agree to have a private third party help them reach a settlement regarding the amount of damages, but the third party cannot impose a binding solution or dollar amount of damages on either Trevor or Mark. What type of alternative dispute resolution process are Trevor and Mark using?