Attractions Signs / How and why are these signs changing?

How and why are tourist attraction signs changing?

TODS show motorists the way to tourist attractions, services and facilities. The signs indicate both the direction and the number of kilometres to the location of a wide variety of attraction sites. The symbols used on the signs are developed by Alberta Transportation and are consistent with nationally recognized symbols. All symbols are white on blue EXCEPT Hospital and Airport symbols, which are nationally recognized as white on green.
Tourist attractions are categorized into Destination Attractions, Major Attractions or Regular Attractions. Generally, larger attractions have larger signs. With large facilities, additional directional signs are permitted further away from the attraction. Small communities with a population of less than 15,000 are permitted to erect a Community Attractions and Facilities Sign at their highway entrance or highway access showing the significant facilities and attractions within that community. The signs make use of the above facility symbols in various ways.