In Pictures: Day 4: William and Kate spend the day in Quebec City
There were complaints at the beginning but the experiment with one of the world's first carbon levies has resulted in a substantial cut in per-capita fuel usage
The Duke and Duchess of Cambridge arrive at the airport in Charlottetown on Prince Edward Island as part of their Royal Tour of Canada, Sunday, July 3, 2011.
The Duchess of Cambridge chats with young girls as the Royal couple arrive at the airport Sunday, July 3, 2011 in Charlottetown, Prince Edward Island.THE CANADIAN PRESS / Ryan Remiorz
The Duke and Duchess of Cambridge arrive in Charlottetown, Sunday, July 3, 2011.THE CANADIAN PRESS / Paul Chiasson
Kate, the Duchess of Cambridge, greets the crowd during a visit to the Levis Community Celebration as they continue their Royal Tour of Canada Sunday, July 3, 2011, in Levis, Canada.
Catherine, Duchess of Cambridge, greets spectators at Forts-de-Levis in Levis, Quebec July 3, 2011. Prince William and his wife Catherine, Duchess of Cambridge are on a royal tour from June 30 to July 8.
Prince William and his wife Catherine, Duchess of Cambridge, wave as they leave the airport in Quebec City July 3, 2011.REUTERS / Mathieu Belanger
The Duke and the Duchess of Cambridge leave Fort Levis in Levis, Quebec on Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
The Duke and the Duchess of Cambridge visit Fort Levis in Levis, Quebec on Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
The Duchess of Cambridge greets people during a visit to Fort Levis in Levis, Quebec on Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
The Duke of Cambridge inspects a group of children dressed as British soldiers as he and the Duchess of Cambridge visit Fort Levis in Levis, Quebec on Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
The Duke of Cambridge inspects a group of children dressed as British soldiers as he and the Duchess visit Fort Levis in Levis, Quebec on Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
The Duchess of Cambridge speaks peolpe int he crowd following a ceremony at city hall Sunday, July 3, 2011 in Quebec City.THE CANADIAN PRESS / Jacques Boissinot
The Duke of Cambridge speaks to a young girl following a ceremony at city hall in Quebec City, Sunday, July 3, 2011.THE CANADIAN PRESS / Jacques Boissinot
Prince William delivers a speech during a ceremony at Quebec city hall on the fourth day of a nine-day tour of Canada with his wife Catherine, Duchess of Cambridge, on July 3, 2011.ROGERIO BARBOSA / AFP / Getty Images
The Duke of Cambridge, Quebec Premier Jean Charest and Quebec City Mayor Regis Labeaume stand on the reviewing stand as the Royal 22nd Regiment marches past with Baptiste, the regimental mascot, during a ceremony at city hall in Quebec City, Sunday July 3, 2011.THE CANADIAN PRESS / Adrian Wyld
One of the Governor General's foot guards is seen with the GG's mascot goat "Baptiste" as the Duke and the Duchess of Cambridge arrive to the Citadel in Quebec City on Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
The Duke of Cambridge inspects members of the second battalion of the Royal 22nd Regiment at city hall in Quebec City, Sunday, July 3, 2011.THE CANADIAN PRESS / Jacques Boissinot
Prince William reviews the troops during a ceremony at City Hall in Quebec City on the fourth day of a nine-day tour of Canada with his wife Catherine, Duchess of Cambridge, on July 3, 2011.ROGERIO BARBOSA / AFP / Getty Images
The Duke of Cambridge inspects the Royal 22nd Regiment honour guard during a ceremony at city hall in Quebec, Sunday July 3, 2011.THE CANADIAN PRESS / Adrian Wyld
Prince William plays table soccer during a tour of the Maison Dauphine in Quebec City on July 3, 2011.MATHIEU BELANGER / AFP / Getty Images
The Duke and Duchess of Cambridge applaud as they tour la Maison Dauphine, a youth shelter, in Quebec City Sunday, July 3, 2011.
The Duke of Cambridge talks to young man after he performed a juggling act as he tours la Maison Dauphine, a youth shelter, in Quebec City, Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
The Duke and Duchess of Cambridge greet youths as they tour la Maison Dauphine in Quebec City Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
Catherine, Duchess of Cambridge, takes part in a trick during a tour of the Maison Dauphine in Quebec City July 3, 2011.REUTERS / Mathieu Belanger
The Duke of Cambridge gets a reaction from youths as he tours la Maison Dauphine, a youth shelter, in Quebec City, Sunday, July 3, 2011.THE CANADIAN PRESS / Sean Kilpatrick
Catherine, Duchess of Cambridge, arrives with her husband Prince William (obscured) at the Maison Dauphine in Quebec City July 3, 2011.REUTERS / Mathieu Belanger
Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge talk to Konrad Sioui as they disembark HMCS Montreal on July 3, 2011 in Quebec.Chris Jackson / Getty Images
Prince William and his wife Catherine, Duchess of Cambridge, disembark the HMCS Montreal in Quebec City July 3, 2011.REUTERS / Phil Noble
Prince William and his wife Catherine, Duchess of Cambridge, disembark the HMCS Montreal in Quebec City on July 3, 2011.CHRISTINNE MUSCHI / AFP / Getty Images
The Duke and Duchess of Cambridge leave the HMCS Montreal as they arrive in Quebec City, Sunday July 3, 2011.THE CANADIAN PRESS / Adrian Wyld
Prince William and his wife Catherine, Duchess of Cambridge, walk on board the HMCS Montreal in Quebec City July 3, 2011.REUTERS / Phil Noble
Catherine, Duchess of Cambridge, greets members of the band following a prayer service on board the HMCS Montreal in Quebec City July 3, 2011.REUTERS / Phil Noble
Britain's Prince William and his wife Catherine, Duchess of Cambridge, take part in a prayer service on board the HMCS Montreal in Quebec City July 3, 2011.REUTERS / Christinne Muschi
The Duke and Duchess of Cambridge take part in a morning prayer service on board HMCS Montreal Sunday, July 3, 2011.THE CANADIAN PRESS / Adrian Wyld
The Duke and Duchess of Cambridge take part in a religious ceremony on HMCS Montreal in Quebec City , Sunday July 3, 2011.THE CANADIAN PRESS / Adrian Wyld