I drive past the site, on the A421, fairly regularly, including times when Universal visitors are most likely to be arriving or departing. Typically I’m connecting between the M1 and the A1, so taking the main roads likely to be used most by Universal guests.
Generally the traffic flows very well. The A1/A421 Black Cat junction can get gummed up, but work has already started to completely transform that interchange, which I’m sure will cope with very high volumes of traffic. That work is due for completion Spring 2027, well before Universal might open.
The other problem is the M1/A421 junction, which can also get gummed up with traffic trying to join the M1, especially to travel towards London. I think that will need to be addressed otherwise the extra traffic, mostly leaving at the same time from Universal’s end of day, will be a problem. I was very pleased to see Stewartby parish council mention that this interchange was being examined by Highways England (or whatever they are now called).
Overall, the travel infrastructure is already excellent for the Universal site, and with some tweaks (much of which is already in hand) I think will easily cope with the forecast visitor traffic. Should ensure locals and visitors are equally happy.