Instructions
Press the "A" button on the Wii remote to bring up your Tools menu.
Use the Wii remote's D-pad to highlight the "Construction" option and press the "A" button.
Highlight the "Transportation" option and press the "A" button.
Highlight the "Highway" option and press the "A" button.
Point the Wii remote at the Wii system's sensor bar.
Press and hold the "A" button and move the Wii remote around to move the cursor on the screen and draw a highway on your SimCity map. When you are finished drawing the highway, release the "A" button to save your changes and finish the highway.