can i tell the route to avoid highways, toll roads, and/or hov (carpool) lanes?

Yes.  From the main Cricket Navigator screen, select Menu (Left Soft Key) and then Preferences.  Select Navigation Preferences, then Trip Settings, then Avoid.  Use the Track Ball to highlight an option you want to change, and use the Track ball to toggle the option on or off.  A checked box means that your routes will be calculated to avoid that type of road.  When done, press OK to save the settings.