Hey there! That's actually a really common question for municipalities and business districts looking to manage public smoking areas. The best approach combines security, accessibility, and practicality.
First, you'll want to select a sturdy, weather-resistant ashtray made of metal or heavy-duty plastic. Look for models specifically designed for side-mounting - they typically come with pre-drilled holes and appropriate hardware.
Positioning is crucial. Mount the ashtray at approximately chest height (around 4-5 feet) on the side of the trash bin, making it easily visible and accessible. Avoid placing it too close to the trash opening to prevent people from confusing the two.
For actual installation, use rust-resistant bolts rather than screws. Drill through the trash bin's metal surface (if it's metal) and secure with lock washers and nuts on the interior side. For plastic bins, you might need to use large washers to distribute the pressure and prevent cracking. Some people add a bead of waterproof sealant around the mounting bracket to prevent water seepage.
Consider the local climate too - in windy areas, you might want a model with a covered top or wind-resistant design. And don't forget regular emptying and cleaning - make sure maintenance staff can easily detach the unit if needed.
The key is making it convenient enough that people will actually use it, while durable enough to withstand public use and weather conditions. Hope this helps with your urban planning project