How is mail partitioned in a delivery truck?

Mail is partitioned in a delivery truck primarily using bins or postal bags to separate different routes or types of mail. This method is efficient for organizing and retrieving mail quickly during delivery. Each bin or bag is designated for a specific route or category, allowing carriers to access the mail they need without unnecessary searching. This approach streamlines the delivery process, enhances organization, and ensures that the mail is delivered to the correct locations in an optimal manner.

The other methods mentioned, though they might seem effective in isolation, do not provide the same level of practicality for bulk mail handling. For instance, using individual envelopes for each address would be cumbersome and inefficient, while organizing according to delivery times could lead to confusion and require constant monitoring. Although color-coded labels can be helpful for sorting at a central location, they are not the primary method for partitioning mail in the delivery truck itself.