Under normal circumstances, the ambulance bay works well. But during a no-notice or mass casualty event, it will get blocked You need to re-route traffic and block off the turn around with stretchers, wheelchairs, and anything else you can find to prepare for arriving casualties. You may have to get creative.
For more lessons learned from no-notice events, take a look at the Crisis Medicine First Receivers ONLINE course - https://www.crisis-medicine.com/cours...