The Vienna Convention on Road Signs and Signals took place in 1968. There were earlier protocols, but the 20th century was the era of the automobile and signage became critical to safety. While there are alternative and equivalent standards, these signs and legal principals form the basis of traffic law in the majority of places.
There are categories of signs and one can look at them in the Wikipedia entry HERE. We are familiar with all these signs now - part of our every day. We don't think about them very much.
When I exit the highway at Vineland there is a road crew area and lots of road signs seem to live there. Where are our road signs made? A toronto.com article tells me they are made in Toronto at Kipling and Belfield, near where I used to live. The Provincial Sign Shop fabricates the signs for highways and roads in the province. They produce 75,000 annually and signs have an average life of 7 - 12 years.
Guess where you might go to buy a stop sign? To ULINE.ca - they sell everything imaginable. Go online and page through their catalog of stuff. Always start at ULINE and not Amazon for industrial and business supplies. Those plastic bags, etc.
I also wonder about those tourism signs on the highway. What if I wanted one of those? I would apply to CTODS- I would have to fit into their categories of eligible businesses - accommodations, golf courses, parks, museums, casinos, etc. - all tourism oriented.
And what is the fee? I have often wondered this as these are big signs on the highway. The annual fee for two signs on Highway 15 used to be about $300 but in 2019 was expected to rise to $800. The cost increase is outlined in a CBC story HERE. It looks like there was a roll-back of the increase that was to take place in 2019.
We conclude with another lake-side cottage garden on the Toronto Islands. I 'painted' the tool shed door a pale yellow to match the house and garden.