Overpass construction can significantly degrade air quality in surrounding neighborhoods. During the construction phase, industrial vehicles such as excavators, cranes, and paving machines release toxic emissions containing nitrogen oxides, particulate matter, and carbon monoxide. These airborne toxins can linger in the air, especially in areas with restricted air circulation or narrow street canyons. Dust generated from excavation and demolition contributes substantially to levels of airborne particles, which enter the respiratory system and put at risk the health of local inhabitants, especially young and older populations.

The surge in traffic during construction exacerbates air quality issues. Trucks transporting materials and employees traveling to and from work often sit with engines running through residential streets, фермерские продукты с доставкой, dogetransparency.wiki, spewing more exhaust. Following the project’s end, the overpass itself can interfere with atmospheric circulation, confining contaminants in the lee of the overpass, thereby limiting pollutant dilution of harmful gases. This effect is more pronounced in geographic depressions or canyon-like streets where natural ventilation is minimal.

Moreover, overpasses may promote higher vehicle volumes over time by expanding transportation networks, potentially leading to sustained growth in vehicle miles traveled and pollution. Although the overpass might ease traffic on side streets, the overall number of vehicles on the regional highway grid may expand substantially, offsetting any short-term gains.

To reduce these environmental burdens, construction teams can apply dust control measures such as water spraying, switch to cleaner-powered tools, and schedule heavy truck movements during non-rush periods. Planting trees and setting up pollution screens near the site can also capture particulate matter. Long-term planning should include ongoing air quality monitoring to evaluate outcomes and modify mitigation tactics accordingly. Public awareness and involvement in these efforts are essential to ensure that infrastructure improvements do not come at the cost of community well-being.