eLOT
Enhanced Line-of-Travel — a USPS sequencing system that assigns a sort order to addresses within a carrier route based on the carrier's actual delivery path.
eLOT (Enhanced Line-of-Travel) provides a numeric sequence number for every delivery point on a carrier route, reflecting the order in which the carrier actually visits each address. When mail is pre-sorted in eLOT sequence, it arrives at the delivery unit in near-walk-sequence order, reducing the time carriers spend casing (manually sorting) mail.
Each address receives a 4-digit eLOT sequence number and an ascending/descending flag indicating which side of the street the carrier serves first. CASS-certified software appends eLOT data during address processing.
Mailers who sort by eLOT sequence can qualify for walk-sequence discounts on saturation and high-density mailings. The eLOT database is updated quarterly by the USPS.