Analysis of the impact of urban rail transit noise on surrounding residential areas

While urban rail transit improves transportation convenience, it also impacts residential areas along the route, including noise and vibration, which in turn impacts real estate prices. The mechanisms of these impacts are complex, requiring a comprehensive analysis from multiple perspectives, including environmental, health, and economic considerations.

Noise impact analysis

Rail transit noise primarily comes from wheel-rail interaction and equipment system noise. Wheel-rail noise includes rolling noise, impact noise, and curve squeal, while equipment noise includes noise from traction motors, braking systems, and warning signals. Elevated lines are primarily characterized by mid- to high-frequency noise ranging from 500 to 2000 Hz, while underground lines are primarily characterized by low-frequency noise ranging from 50 to 63 Hz. Low-frequency noise, due to its strong penetrating power, has a more significant impact on high-rise residential buildings.

Noise attenuates logarithmically with distance, decreasing by approximately 6 dB(A) for every doubling of distance. Severe, moderate, and mild impact zones correspond to within 25 meters, 50–100 meters, and more than 200 meters from the tracks, respectively. Source control measures, such as rail grinding, can reduce noise by 3–5 dB(A). Floating slab tracks and sound barriers can also effectively reduce vibration and noise.

Noise has multiple health impacts, including physiological, psychological, and social. Long-term exposure can lead to hearing loss, cardiovascular disease, and even neurodegenerative disorders, while also causing anxiety, sleep disorders, and other problems. On a societal level, noise disrupts teaching and work efficiency, increasing medical and economic costs.

Among typical cases, the phenomenon of "meeting standards to disturb residents" has occurred in Shenzhen, Wuhan, Shanghai and other places, reflecting that the current standards are out of touch with the actual feelings of residents, and that problems such as unclear responsible parties and restricted project implementation are prominent in the governance process.

Vibration impact analysis

Vibration originates from wheel-rail interaction and propagates through the track, ground, and building structure, exhibiting different characteristics between underground and elevated sections. The vibration frequency ranges from 20–80 Hz, which can easily induce resonance in the building structure and cause secondary structure-borne noise.

Long-term vibration exposure to buildings can cause damage to non-structural components and material fatigue, while also causing physical and psychological problems such as sleep disturbances and headaches. Economically, residential properties in vibration-sensitive areas are typically 8%–15% lower in value than those in non-vibration areas, and transaction times are also longer.

Case studies have shown that vibration and noise on Shenzhen Metro Line 6 are synergistically disturbing residents, while measured vibration on Xi'an Metro Line 4 is lower than predicted. The hidden vibration of Montpellier makes control difficult. Guangzhou Metro Line 14 successfully reduced vibration by 25 dB using a steel spring floating slab trackbed, demonstrating the effectiveness of technical measures.

Real estate price impact analysis

Rail transit has a dual impact on surrounding housing prices. The positive effect primarily manifests in the premium generated by improved accessibility, which follows the principle of "distance decay." For example, within 500 meters of a Changsha subway station, there's an 8–12% premium. Convenient commuting, comprehensive amenities, and perceived value are the primary drivers of this premium.

Negative effects often stem from environmental disturbances like noise and vibration, which reduce living comfort. Research in Singapore shows that for every kilometer closer to rail, housing prices fall by 3–4%. In places like Shenzhen and Wuhan, housing prices have depreciated despite meeting standards, demonstrating the market's decisive role in housing prices.

Different regions show obvious spatial differences: emerging areas have significant premiums, while mature areas have limited premiums; areas near stations may experience value loss due to noise and pedestrian interference.

Protective measures and regulatory enforcement

Engineering measures include rail grinding, floating slab tracks, and sound barriers. Each additional meter of sound barrier height reduces noise by approximately 3 dB. Fully enclosed barriers are most effective but are costly. Architectural measures, such as soundproof windows, can reduce noise by 20–50 dB , and window types can be customized to meet site noise requirements.

Planning should incorporate vibration and noise reduction concepts during the design phase, such as optimizing track structure, building layout, and ventilation systems.

National standards, such as the "Noise Environment Quality Standard" (GB 3096-2008), set noise limits, but they focus on mid- and high-frequency noise, insufficiently covering low-frequency vibrations and residents' subjective perceptions. While Beijing, Chongqing, and other regions have supplemented these with local regulations, such as clarifying protective distances and implementing full lifecycle management, these still face challenges in implementation and the shirking of responsibility.

There are still some problems in the current noise and vibration control, and it requires collaboration among multiple departments to achieve the transition from "meeting standards and complying" to "healthy and friendly".