State of Mexico Begins Hoy No Circula Program Amid Air Issues

On Jan. 1, 2026, the Hoy No Circula vehicle circulation restriction program took effect in metropolitan areas across Central Mexico. The program, which began operating in 22 municipalities across the metropolitan areas of the Valley of Toluca and Santiago Tianguistenco in the State of Mexico, will restrict the circulation of vehicles with verification holograms 1 and 2 from 5:00. to 22:00, Monday through Saturday. The policy aims to reduce emissions of pollutants such as particulate matter, nitrogen oxides, ozone, and carbon monoxide, while promoting the use of public transportation and long-term fleet renewal.

On the same day, the Environmental Commission of the Megalopolis (CAMe) activated a Phase I regional atmospheric environmental contingency for PM2.5 in southeastern areas of the Valley of Mexico, including parts of Mexico City. Authorities attributed the deterioration in air quality to widespread use of fireworks and bonfires during New Year’s Eve, combined with weak winds and atmospheric stability that limited pollutant dispersion.

CAMe reports that at 8:00 a.m., PM2.5 concentrations reached 107.3µg/m3 at the Santiago Acahualtepec monitoring station in the Iztapalapa borough, prompting the vehicle circulation restrictions. Under the contingency, vehicles with green stickers and verification holograms 1 and 2 were restricted from circulating in affected areas, while vehicles with holograms 0 and 00, as well as those with yellow, red, pink, and blue stickers, were allowed to operate. Authorities say that if air quality conditions remain poor, a possible “Doble Hoy No Circula” with restrictions twice as strict, may be implemented later in the week.

At 9:00 a.m. on Jan. 2, PM2.5 concentrations of 88µg/m3 and 83µg/m3 were recorded at the Almoloya de Juárez and Xonacatlan monitoring stations, respectively. As such, state authorities announced continued circulation restrictions in the Valle de Toluca and Santiago Tianguistenco metropolitan areas. These include a full ban on vehicles with hologram 2; restrictions on hologram 1 vehicles with license plates ending in 2, 4, 6, 8, and 0; and limits on certain hologram 0 and 00 vehicles. Cargo transport vehicles face time-based restrictions, while 50% of liquefied petroleum gas delivery units without dry disconnect valves are restricted based on plate numbers.

During periods of vehicle circulation restrictions, exemptions apply to electric and hybrid vehicles, emergency and public service units, school and personnel transport, vehicles for people with disabilities, regulated hazardous materials transport, and freight operators enrolled in environmental self-regulation programs.

Researchers explain that prolonged exposure to air pollutants negatively affects physical health, increasing the risk of heart attacks and accelerating cognitive decline in the elderly population, reports MBN. The Spanish Society of Cardiology (SEC) and the Spanish Heart Foundation (FEC) found that when PM₂.₅ particle concentrations exceed 10µg/m3, there are 22 additional heart attacks per 1,000 hospitalizations in the three days following exposure. Moreover, when concentrations reach 25µg/m3, the risk of dying during hospitalization due to a heart attack rises by 14%.