I think there may be a difference in the asphalt oils. If I’m not mistaken, the Middle East has ‘light’ crude oil while many places in North America have ‘heavy’ crude oil. I’m not a Petrochemical engineer, but your oil may have more ‘light ends’ that need to evaporate to give the needed stability before opening to traffic. What a change of fortune it would be for the Middle East to have to import oil products from North America!!
There may be a polymer that could be incorporated to give the desired early stability that you desire.
