Coaches are used at State Visits, at Royal Weddings, at Royal Funerals, at the Trooping, at the State Opening of Parliament, at Garter Day, at Ascot race days so why would it not be used for THE most ceremonial State event of all?
because they are uncomfortlabe, very expensive to maintain and beginning to look out of date. Cars are being used now at royal weddings... so I think its possible that they'll give up using them altogether.....
Cars are used to convey the bride and her father, both commoners, to the church. Carriages are used for the royal couple when they return from the church. Even Queen Elizabeth, the Queen Mother arrived in a car whereas her daughter, Princess Elizabeth arrived in a carriage as did the rest of the royal family. Princess Anne, being royal, also arrived at the abbey by carriage.
As to the Coronation, while it feels a bit premature to be discussing it with HM still hale and hearty, it is what it is. The government of the day will have a huge say in how grand it will all be. It will be the premier tourist event in the UK for decades and the government, rather than seen to be seen scrimping and cutting costs to the bones, will be pushing the boat out, especially after Brexit and hopefully Covid.
It will be an occasion to celebrate the very best in British, the pageantry, the carriages that allow people to get fantastic shots at the new King and Queen and the BRF, the mounted escorts, military bands and the military route liners. The heads of all the Commonwealth Countries present and more than a few past, UK politicians, Heads of State and Ambassadors, etc.
In the words of the old Chinese saying "may you live in interesting times", we all are and it is dire and dreary and mostly pretty joyless so, come the event, being a pragmatist, when it come HM's funeral they will see her off in style. But, the Coronation of the new Monarch will be an opportunity to let rip with flypasts, brass and pipe bands, bunting and balloons. If that doesn't kick start or double commerce and tourism I don't know what would. It will also be a Commonwealth Celebration too so the Coronation will represent us too.