A mileage log, in its purest form, is a ledger of trust: a column for dates, a column for destinations, a column for miles claimed, and no reliable mechanism for verifying any of it beyond the claimant's own arithmetic and conscience. Companies require them anyway, on the theory that a form, once filled out, carries more weight than a memory.
In practice the specimen is completed in one of two modes. The diligent mode logs each trip the evening it occurs, odometer read twice for accuracy, client name noted in full. The reconstructive mode is filled out quarterly, from memory, using a calendar and a general sense of where the territory usually requires driving, rounded generously upward. Both modes produce numbers the accounting department accepts without comment, since auditing a mileage log costs more than any mileage log has ever cost the company.
Paper versions, when they still circulate, show a distinctive wear pattern: creased along the fold from riding in a glovebox, ink smudged where a coffee cup once sat on the current week's row. Digital versions show no wear at all, only a small submitted badge, which feels like a loss, though nobody can quite say of what. How many of the miles claimed this quarter, across how many logs, actually happened, that's not really this guide's business.