<![CDATA[ABSTRACT A National roads play a vital role in supporting mobility and goods distribution; however, high traffic volumes may reduce air quality in surrounding residential areas. This study aimed to analyze the relationship between traffic density and PM2.5 and CO₂ concentrations, examine the influence of residential environmental characteristics on air quality, and evaluate community environmental comfort along Sumpah Pemuda Road, Mojosongo, Surakarta. A field survey was conducted by measuring PM2.5, CO₂, and traffic volume during morning, afternoon, and evening periods at several observation points, complemented by interviews with 30 respondents. Data were analyzed using descriptive comparative analysis. The results showed that peak traffic density reached approximately 10,000 vehicles/hour on weekdays and decreased to 2,724 vehicles/hour on weekends. CO₂ concentrations were predominantly classified as high to hazardous, while PM2.5 levels ranged from good to hazardous. Residential areas located within ≤10 meters of the roadside experienced higher pollutant exposure, and most respondents reported that poor air quality reduced environmental comfort. The novelty of this study lies in integrating air quality measurements, residential spatial characteristics, and community perceptions to support air pollution mitigation strategies along national road corridors. The study concludes that increasing traffic density is associated with higher PM2.5 and CO₂ concentrations, highlighting the need for green belts, additional roadside vegetation, and integrated traffic management to improve air quality. ABSTRAK Jalan nasional berperan penting dalam mendukung mobilitas dan distribusi barang, namun tingginya lalu lintas berpotensi menurunkan kualitas udara di kawasan permukiman. Penelitian ini bertujuan menganalisis hubungan kepadatan lalu lintas dengan konsentrasi PM2.5 dan CO₂, pengaruh karakteristik permukiman terhadap kualitas udara, serta tingkat kenyamanan masyarakat di sepanjang Jalan Sumpah Pemuda, Mojosongo, Surakarta. Penelitian menggunakan survei lapangan melalui pengukuran PM2.5, CO₂, dan volume kendaraan pada pagi, siang, dan sore hari di beberapa titik pengamatan serta wawancara terhadap 30 responden. Data dianalisis secara deskriptif komparatif. Hasil menunjukkan kepadatan lalu lintas tertinggi mencapai sekitar 10.000 kendaraan/jam pada hari kerja dan terendah 2.724 kendaraan/jam pada akhir pekan. Konsentrasi CO₂ didominasi kategori tinggi hingga berbahaya, sedangkan PM2.5 berkisar dari kategori baik hingga berbahaya. Permukiman berjarak ≤10 meter dari tepi jalan mengalami paparan polutan lebih tinggi dan mayoritas responden menyatakan kualitas udara menurunkan kenyamanan lingkungan. Kebaruan penelitian ini terletak pada integrasi pengukuran kualitas udara, karakteristik spasial permukiman, dan persepsi masyarakat sebagai dasar mitigasi pencemaran udara di koridor jalan nasional. Penelitian menyimpulkan bahwa peningkatan kepadatan lalu lintas berkaitan dengan naiknya konsentrasi PM2.5 dan CO₂, sehingga diperlukan penguatan jalur hijau, penambahan vegetasi, dan penataan lalu lintas terpadu.]]>
