On a normal day, making use of the cruise control to help keep a constant speed allows you to save on fuel consumption.
WHY PLANNING YOUR JOURNEYS AND USING CRUISE CONTROL
Avoid busy times: The better you plan your journey, the more chances you have to avoid being stuck in traffic. Try to avoid peak times as much as you can. By doing so you will save time but also from 5 to 10% on the amount of fuel burnt.
Have a smooth and economical drive by planning and using all tools available to improve your journey.