Security measures include an extensive network of automatic number plate recognition (ANPR) technology and CCTV alongside hostile vehicle mitigation (HVM) barriers to prevent the use of cars or vans in an attack.
If too many people descend on Windsor, the town will be put on virtual lock-down, with trains no longer stopping to drop passengers off at its stations and people turned away from crowded processional routes.
More than 100,000 people from across the world are expected to travel to Windsor to watch Harry and Meghan tie the knot.
Police say they are trying to balance robust security measures with a desire to allow the thousands of onlookers to enjoy the atmosphere of the wedding.
Details of Thames Valley Police's operation to safeguard the newlyweds, their guests and spectators have been released, with airport-style security scanners and bag searches also planned in Windsor.
Local businesses and visitors "can expect to see an increased police presence" ahead of the wedding including armed police, search dogs and helicopters, the police said.
During the carriage procession, the streets within Windsor Castle will be lined with members of the Windsor Castle Guard formed by the 1st Battalion Irish Guards and other Armed Forces personnel.
The wedding day will feature regiments and units that have a special relationship with Prince Harry, who served in the military for a decade and was deployed on frontline duties twice to Afghanistan.
In the show, Markle, who will get married to Prince Harry on May 19, plays lawyer Rachel Zane, who is engaged to Mike Ross (Adams). Symbolism for her love of Prince Harry?
Assistant Chief Constable David Hardcastle, strategic commander for the wedding, said: "We are proud to police the Royal Borough of Windsor and Maidenhead".
The force assured residents that day-to-day policing and the response to incidents would not be affected by the Royal wedding.