Unique Mine Cart / Roller Coaster Setup

I’m wanting to create a roller coaster style setup using physics and a rigid body to add some reallism. However I’m having issues deciding how to approach it. Most roller coaster style setups use some kind of follow spline / itween setup however my track setup is more dynamic. Some pieces of the track will be missing requiring the user to jump to the next section as well as conatin switch sections that will require the user to hit a track switch to change their course. I know I need some kind of follow path setup but with some flexibility. I don’t want the mine cart to simply slide along the track. I intend on using the wheel colliders on the cart to add some physics however the cart needs to follow a path (I cant have the users steering the cart…) However the cart needs to be able to jump and fall off the tracks if necessary. I’m afraid if I use the spline controller it will “drag” the cart along the track and remove the realism…I’m wondering if I need to have an invisible game object follow the path and then the cart will follow the game object and leave the up and down axis free so if the cart is following the game object and their is no track it will fall off and end the level. Any thoughts on how to achieve this would be great. Also I was wondering if ITween would be the best route to try? And would I need multiple splines to achieve the break in the tracks as well as the “sub” track sections where a track switch would be?

Thanks,

I’m sorry but my English is not so good, if I well understood
think this explain better than me

http://answers.unity3d.com/questions/52216/Hinge-Joints-distance-to-connected-body.html

Hallo, I think you are in right way
try look at Fixed Joint or Hinge Joint