San Luis Potosí → Zacatecas · Autopista 57D México-San Luis Potosí
On heavy-rain or dense-fog days the San Luis Potosí, San Luis Potosí, to Zacatecas, Zacatecas, leg routinely demands well more than the 2h 28m estimated: Autopista 57D México-San Luis Potosí carries known hydroplaning hot spots and reduced-visibility corridors that justify dropping to 35 mph through a few short stretches. The outbound run covers 222 km (138 miles) over varied topography between San Luis Potosí (the capital potosina y nodo logístico que conecta el Bajío con el norte del país) and Zacatecas (the capital zacatecana y patrimonio minero colonial reconocido por la UNESCO), demanding sharper attention on mountain descents and shoulder-less curves. Before pulling out, check brake-pad wear, tire tread depth, and washer-fluid level in the reservoir. Fuel spend holds near MXN 447.70 for the 18.5 liters (4.9 gallons) consumed. Even in adverse conditions, the flat tariff of MXN 6.50/km guarantees the standard outbound payout of MXN 1443.00 — log any incidental costs (extra toll, mandatory meal, emergency lodging) in a separate field on the Clara receipt. For the Canadian professional driving the 222 km between San Luis Potosí and Zacatecas, reimbursement of MXN 1443.00 stays excluded from T4 employment income provided the per-kilometre rate matches the CRA's reasonable allowance benchmark for the province. Canadian employers typically reimburse at the CRA reasonable per-kilometre rate (61¢ for the first 5,000 km in 2024) so the payment is excluded from T4 employment income. Keep the GST/HST-compliant fuel receipt from any NRCan-tracked retail network station used during the trip — Canada Revenue Agency (CRA) auditors regularly verify fuel-receipt GST/HST when reviewing T2200 declarations of conditions of employment. The San Luis Potosí→Zacatecas mileage must be logged with date, business purpose, opening and closing odometer readings inside the corporate expense system before month-end close to remain deductible.