Forcing all deliveries to happen in the early morning sounds like a massive pain in the butt.
For example: Forcing a lunch/dinner restaurant to have people there early to deal with inventory or delivering inventory to a diner during breakfast rush are both far from ideal.
Any industry that routinely has to get materials (e.g. skilled trades) delivered will be inconvenienced by not being able to take delivery during mid-morning or after lunch, this can unnecessarily stretch out jobs (and cost more $$).
I guess if the only industries in your city are white collar or tourism it's fine.
Better to just not allow noncommercial vehicles during certain times.