Consolidating less-than-truckload shipments across customers

Our regional distribution centre sends many half-empty trucks because each customer's orders are shipped separately on their requested day. Fuel and driver costs keep rising, and customers are unwilling to pay more.

We are testing fixed delivery days per area with an incentive for customers who accept them, and a planning tool that combines orders into multi-drop routes. Some large customers resist losing flexibility. How did you convince customers to accept consolidated delivery schedules, and what savings did you achieve?