Abstract: Fire rescue in special highway tunnels has always been a challenge in the fields of public safety and highway transportation. Due to the characteristics of "long line type and double hole separation" of extra long highway tunnels, the accessibility of fire rescue varies greatly in different sections and driving directions, making it difficult to accurately evaluate using existing methods. Therefore, this article collects fire rescue demand points equidistant from different driving directions of lanes in a special highway tunnel, and then calculates the average travel time of fire rescue demand points to measure the accessibility of fire rescue. A time weighted evaluation model for the overall average accessibility of fire rescue in regional extra long highway tunnels has been established. To verify the effectiveness of the model, taking the extra long highway tunnel in Guizhou Province as an example, a total of 960 fire rescue demand points were collected, and the real-time rescue travel time was simulated through the network map application programming interface. 337 estimation scenarios were set up throughout the entire week (7 consecutive days), and a total of 323 520 valid evaluation samples were obtained. The overall average accessibility of fire rescue in Guizhou Province's extra long highway tunnels is calculated to be 0.242, with an average travel time of 2 560.68 seconds and an average travel distance of 32 870.18 meters. The result level is "poor", indicating that the accessibility of fire rescue in this area's extra long highway tunnels is low. From the perspectives of safety and economy, dedicated fire brigades can be established for extra long highway tunnels, and fire rescue points can be set up at toll stations or service areas along highways. The evaluation model proposed in this article can provide key methods and data support for enhancing the fire rescue capabilities of extra long tunnels from a regional perspective.

Key words: extra-long highway tunnels, fire； fire service, real-time road conditions, accessibility