... need about 240mm slew in about 1050mm length. Hi Howard, You can't use a single transition curve, because such a curve must involve a change of radius. If both ends are straight they are both the same (infinite) radius. Slewing is the easier option. For 2mm/ft that's not really too severe as a slew -- I suggest you use a "mode 2" slew with the slew shape factor set to the default of 100. The minimum radius is then about 600mm (24"): slew_mode2_100factor.png Admittedly it's not very prototypical to use such a large amount of slew. The proper approach is to use 3 separate transition curve templates. A central S-curve transition to create the reverse curves, and then an easement from the straight at each end. If you first create the easements at each end, you can then use the "make transition" function to link an S-curve between them. Before using "make transition" make sure to move the peg to the inner ends of the first templates, ...