I agree with Shosh and Bobbi. The Merge uphill can be interesting in a Smart.
I like to arrive on the freeway at around 70 +, than slow if I must. A couple times I have been caught behind the power curve in "D" while the trans decided to do a gear change.
Nowadays I just use the stick and wind her out. Works perfect every time.

(High time L.A. driver here with 10.1 k on Smartie's ode.) A2Jack.