Road puddles often make threats for vehicles and pedestrians. According to road accidents data in Seoul, road puddles could lead to fatal road accidents. Under ‘wet’ road surface conditions, the accident case accounts to 8.2% and death toll to 12.2%. Fatality rate under ‘wet’ road surface conditions increases by 1.6 times compared to other times. This study analyzes problems of road puddles and suggests policy frameworks for better management of roads in Seoul.

First, the study reviews concepts, previous studies, and institutional frameworks and management operations of road puddles.

Second, by using recent road accident data, the study analyzes the relationships of road accidents with weather and road surface conditions in Seoul to draw implications of potentially fatal threats caused by road puddles.

Third, the study analyzes current problems of road puddles in Seoul. Based on several survey data of road pavement conditions and puddles from the Seoul city government, the study carried out desktop GIS analysis by using high-resolution digital terrain model and field surveys before, during, and after raining. Road puddles occur mainly in road pavement, road drainage, and surrounding topographic features. According to a questionnaire survey on road puddles, public officials responsible for road management percept that road puddles are caused mainly by deformation and subsidence of road pavement and by roadside gutter and inlets.

Fourth, in January 2018, the total number of street inlets was 487,364 exhibiting a significant installation difference by the district. Inlets become deteriorated by 63.2% over 30 years of lifespan. The study examines the hydrological suitability of inlets with respect to road puddle section in Seoul. The analysis results implicate that careful installations of Complete the information are necessary by considering the possibility of formation of road puddles.

Fifth, the study suggests the improvements to manage road puddles in Seoul. Since road puddles can occur at any place and at any time due to rainfall, the city government needs to set the focus on road sections, including areas like pedestrian-concentrated areas (e.g., bus stops, subway stations, etc.), surrounding areas of large-scale construction sites, highways and arterial roads where vehicle speeds are high, etc.

The study suggests several strategies for improvement to the management to cope up with road puddles with respect to road pavement and drainage systems. For example, the study suggests the integration of pavement maintenance and road drainage as currently different agencies and department are in charge.

Since it is difficult to anticipate the formation of road puddles with respect to time and place, policies need to focus on rapid response systems but need to strengthen proactive prevention. The study suggests several measures for response and prevention, including carrying out routine surveys, citizen report systems, uses of road surface survey data and social media, etc.