Construction Impacts On The Environment: Strategies For Improvement
Pavement construction practice has changed significantly over the last several decades. Utilizing new technologies have resulted in improving pavement quality and construction efficiency while decreasing environmental impacts. Recent construction practices, along with an appropriate pavement structural design (see Chapter 4 (.pdf, 3 mb) of the Reference Document that uses appropriate materials (see Chapter 3 (.pdf, 5 mb) of the Reference Document), can provide significant improvements to the overall performance and sustainability of a pavement system. Critical areas of pavement construction that can have a significant effect on the overall sustainability of a paving project include the following:
- Fuel consumption (during material transport from the site, between the plant and the site, and the construction operations themselves).
- Exhaust and particulate emissions.
- Traffic delays, congestion, and noise emissions generated during construction.
- Constructed characteristics of the pavement surface, which impacts surface friction (safety), noise, and possibly fuel efficiency during the use phase.
- Pavement performance and overall life (as a result of construction quality).
The following are the general pavement construction factors that impact pavement system sustainability over the life cycle:
- Construction-related energy consumption.
- Effect on the surrounding area (including particulate and gas emissions, noise, effects on residents and businesses, and effects on wetlands and streams).
- Economics of construction practices, including user costs (due to construction-related traffic delays and normal operations).
Table 1 summarizes several strategies for improving the sustainability of pavement construction operations that are applicable to all highway construction projects, regardless of pavement type. These strategies revolve around four major objectives (reduce fuel consumption and emissions, reduce noise, accelerate construction, and control runoff, erosion, and sedimentation), and the economic and environmental impact and trade-offs associated with each strategy are described. Additional discussion on these strategies is provided in the following sections. See Chapter 5 (.pdf, 5 mb) of the Reference Document for more details.
| Objectives | Sustainability Improving Approach | Economic Impact | Environmental Impact | Societal Impact |
|---|---|---|---|---|
| Reduce Fuel Consumption and Emission | Minimize haul distances | Reduced fuel costs | Reduced GHG emissions and air pollutants | |
| Select appropriate equipment type and size for the job | Reduced fuel costs but may require capital investment | Reduced GHG emissions and air pollutants | ||
| Idling reduction | Reduced fuel costs; may require some capital investment to minimize idling | Reduced GHG emissions and air pollutants | Improved air quality | |
| Use alternative fuels | Varies | Reduced emission | Improved air quality | |
| Retrofit construction equipment, use hybrid equipment, or both. | Will increase costs due to initial capital investment | Reduced GHG emissions and air pollutants | Improved air quality and may decrease construction related noise | |
| Reduce Noise | Construction time restrictions | It may lead to reduction in construction productivity | May increase emissions if construction is prolonged | Less noise and may affect air quality |
| Equipment maintenance or modification | Increased capital investment | No environmental impact | Less noise | |
| Accelerate Construction | Effective traffic control and lane closure strategies | Reduced fuel costs for users and agency | May reduce traffic delays and associated emissions | Less traffic disturbance |
| Establish performance goals and measures for work zones | Reduced fuel costs for users and agency costs | May reduce traffic delays and associated emissions | Less traffic disturbance | |
| Use project management software for construction sequencing and managing traffic delays | Reduced fuel costs for users and agency; extra effort for agency/contractor | May reduce traffic delays and associated emissions | Less traffic disturbance | |
| Implement intelligent transportation warning systems | Increased agency costs | May reduce traffic delays and associated emissions | Less traffic disturbance and improve work zone safety | |
| Control Erosion, Water Runoff, and Sedimentation | Use perimeter control barriers (fences, straw bales, etc.) | May result in increased project costs | Reduced sedimentation, prevent degradation of water quality | No direct impact on society |
| Minimize the extent of disturbed areas | May result in increased project costs | Reduce disturbed areas | May reduce impact on surrounding residential areas | |
| Apply erosion control matting or blankets | May result in increased project costs | Reduced sedimentation | May reduce impact on surrounding residential areas | |
| Store/stockpile away from watercourse | No significant economic impact | May reduce potential water pollution | May reduce potential impact on area water | |
| Improve construction quality to meet specifications | Achieve target density, placement and smoothness requirements | Generally no change or insignificant increases in cost | Reduce environmental impact through good quality materials and longer life pavements | Longer pavement life and lesser intervention |