Public transit infrastructure and heat perceptions in hot and dry climates

Area of Science:

• Urban planning and public health
• Environmental science and climatology
• Transportation engineering

Background:

• Cities aim to increase public transit use for sustainability and health, but extreme heat in hot climates poses a barrier.
• Inadequate bus stop infrastructure fails to provide thermal comfort, potentially exposing riders to health risks.

Purpose of the Study:

• To identify bus stop design attributes and rider coping behaviors that enhance thermal comfort in hot climates.
• To assess the effectiveness of different bus stop designs in mitigating heat exposure.

Main Methods:

• Conducted micrometeorological measurements and rider surveys at various bus stops in Phoenix, AZ, during summer 2018.
• Analyzed physiological equivalent temperature (PET) reductions and rider perceptions of heat and comfort.
• Evaluated the impact of design attributes like shade and materials on thermal comfort and surface temperatures.

Main Results:

• Nearly half of surveyed riders felt hot or very hot, with over half reporting thermal discomfort.
• Shade significantly reduced PET by an average of 19°C, with varying effectiveness throughout the day.
• Sun-exposed surfaces exceeded skin burn thresholds, but shade brought them to safe levels; aesthetically pleasing stops were perceived as cooler.

Conclusions:

• Current bus stop infrastructure in hot climates is insufficient for thermal comfort and can pose health risks.
• Prioritizing thermal comfort in bus stop design, particularly through effective shading, is essential for increasing public transit ridership and achieving urban sustainability goals.