Abstract:To investigate the effects of vehicle dynamic loads on the settlement and mechanical performance of the underground comprehensive utility tunnel in silty soil foundations,a calculation model of the buried comprehensive utility tunnel is established using the finite element software PLAXIS 3D,and a scaled model test is conducted to verify the reliability of the numerical model.By applying a sinusoidal wave to simulate vehicle dynamic loads,the influences of parameters such as tunnel burial depth,elastic modulus of backfill soil,groundwater level,vehicle load amplitude and loading position on the settlement and dynamic response of the tunnel are analyzed.The results show that:1)The settlement at each measurement point significantly increases within the first second,followed by periodic oscillation and stabilization,with the settlement of the soil at the bottom of the tunnel being less than that without the tunnel.2)The tensile stress in the tunnel is mainly concentrated on the inner side of the top slab of the left chamber,the upper outer side and the middle inner side of the left side wall,and the middle inner side of the right side wall,with the maximum tensile stress peak occurring on the upper outer side of the left side wall and the largest fluctuation amplitude generated on the inner side of the top slab of the left chamber.3)The vibration acceleration response of the top slab is larger,as it transmits the vibration acceleration response along the tunnel side walls and the central diaphragm to the bottom slab,with the top slab and side walls stabilizing around the second second,and the bottom slab stabilizing around the first second;after stabilization,the peak vibration acceleration of the top slab is the largest,while that of the bottom slab is the smallest.4)As the burial depth of the tunnel increases,the settlement of the soil at the bottom of the tunnel decreases,and the peak vibration acceleration of the top slab,side walls,and bottom slab decreases,with a recommended burial depth of 2.5 m to 3.0 m;as the vehicle load amplitude increases,the peak tensile stress,settlement,and peak acceleration of the tunnel all increase;the vehicle load applied directly above the comprehensive utility tunnel is the most detrimental to the tunnel,resulting in the maximum peak tensile stress and acceleration,while moving the loading position away from the tunnel's central axis to the left or right generally reduces the peak tensile stress and vibration acceleration of each structure of the tunnel.5)An increase in the elastic modulus of the backfill soil helps to reduce the settlement and peak acceleration of the tunnel.With the increase of groundwater level,the settlement at the bottom of the tunnel initially decreases slightly and then increases.

Abstract:To analyze the actual working performance of the large-span cast-in-place concrete beam combined supporting system,to prevent support overturning accidents during construction,and to optimize structural redundancy design,a monitoring system is established based on the Jinan tram project's three-span continuous beam bridge by deploying high-precision sensors.A method combining real-time monitoring throughout the construction process with finite element simulation is used to study the key mechanical behaviors of the combination system composed of steel pipe columns,Bailey beams,and buckle supports.The results indicate that during the entire construction process,the stress monitoring results of the main components of the combined support system are generally 5％to 15％lower than the finite element calculation results,suggesting that the overall design of the combined support system based on finite element simulation possesses a higher safety reserve;the stress monitoring results of the upper chord member of the Bailey beam at mid-span showed a significantly greater discrepancy compared to the finite element results than the lower chord member at mid-span,indicating that there is a deviation between the internal constraints of the finite element model and the actual working conditions;the stress monitoring results of the diagonal braces between the steel pipe columns are greater than the finite element simulation results,which should be noted during the design phase.

Abstract:To improve vehicle-cargo matching efficiency on online freight platforms,a three-stage supply-demand matching model is proposed that accounts for the needs of carriers,shippers,and the platform.Stage 1 constructs a cargo attribute classification model to identify and eliminate conflicts among different cargo attributes.Stage 2 develops a vehicle information screening model to extract each vehicle's high-frequency delivery regions.Stage 3 formulates a multi-objective matching model with objective functions that maximize carrier profit,minimize shipper cost,and maximize platform revenue.A traditional genetic algorithm is enhanced with a greedy operator,a circle chaotic map,an opposition-based learning strategy,and a simulated annealing mechanism,and the enhanced algorithm is used to solve the model.An empirical analysis is conducted using Guangzhou-origin freight and vehicle postings released by the China Wutong Network.The results indicate that the matching solutions obtained with the improved genetic algorithm outperform those from the standard genetic algorithm in overall loading efficiency and vehicle utilization.Given the same total shipment volume,the improved algorithm completes transport tasks with fewer vehicles,increases the average number of loads per vehicle,and significantly improves load consolidation.It also converges faster and exhibits a smoother,less volatile post-convergence curve.Compared with the standard genetic algorithm,the improved algorithm increases carrier profit by approximately 32.6％,40.6％,48.6％,and 31.3％across four cargo sets,reduces shipper cost by about 3.2％,10.3％,11.5％,and 7.6％,and raises platform revenue by about 0.9％,0.1％,2.4％,and 0.1％,respectively.Overall,the three-stage matching model and the improved genetic algorithm better balance the interests of carriers,shippers,and online freight platforms.

Abstract:To investigate the impact of pollutants generated from the operation of airport ground support equipment(GSE)on air quality and the environment,taking an international airport as the research object,ground support equipment is classified into 17 categories according to their primary purposes,and the emission standards of ground support equipment are statistically analyzed.A calculation method for key operating parameters of ground support equipment is proposed,real-time operational data are collected,and the commonly used operating speeds,load factors,and annual pollutant emissions of ground support equipment are calculated to analyze emission characteristics.The feasibility of electrification upgrade for airport ground support equipment is explored,and a comparative analysis is conducted on the economic benefits,environmental benefits,and operational convenience of two strategies:upgrading existing baggage carts to new equipment complying with China's National Ⅵ Emission Standard versus replacing them with pure electric baggage carts.The research results indicate:1)Among the 17 types of fuel-powered ground support equipment,the top 5 ground support equipment in terms of annual pollutant emissions are baggage carts,catering trucks,aircraft tow tractors,runway maintenance vehicles,and ground support shuttle vehicles.The annual emissions of CO,HC,NOx,PM2.5,and PM10 from these 5 types of ground support equipment account for 76.3％,80.0％,63.3％,85.3％,and 85.5％of the total annual emissions,respectively.2)When the airport replaces existing baggage carts with new equipment complying with China's National Ⅵ Emission Standard,the annual emissions of CO,HC,NOx,PM2.5,and PM10 are reduced by 23.1％,15.4％,37.2％,43.2％,and 43.1％,respectively.3)The initial investment for electric baggage carts is 80 000 yuan more than that for China's National Ⅵ Emission Standard fuel baggage carts,but the annual energy cost savings and annual maintenance cost savings are 16 500 yuan and 357 yuan,respectively,with a payback period of approximately 4.75 years.Electric baggage carts have higher initial investment but lower operating costs throughout their entire lifecycle,demonstrating more significant economic benefits.Electric ground support equipment does not produce harmful substances such as NOx during operation,and the noise generated is 10-20 dB lower than fuel vehicles of the same power.Electric ground support equipment has lower manual maintenance costs and adopts continuously variable transmission structure,improving the operational reliability of ground support equipment and reducing driver labor intensity.

Abstract:To study the cyclic dynamic characteristics of red clay in Nanning area,dynamic triaxial cylindrical specimens(hereinafter referred to as specimens)are prepared for a series of dynamic triaxial tests.The effects of different consolidation confining pressures,cyclic stress ratios,and loading frequencies on the dynamic strength degradation and dynamic deformation evolution characteristics of Nanning red clay are investigated,along with an analysis of the variation patterns of dynamic elastic modulus and damping ratio.The test results indicate that:1)Under different loading conditions(consolidation confining pressure,loading frequency,cyclic stress ratio),the dynamic stress of the specimens decreases rapidly and then tends to stabilize with the increase of the number of cycles.For the same number of cycles,dynamic stress increases with the increase of consolidation confining pressure,while it decreases with the increase of loading frequency and cyclic stress ratio,indicating that consolidation confining pressure,loading frequency,and cyclic stress ratio have a significant impact on the dynamic stress of the specimens.2)Under a consolidation confining pressure of 300 kPa and a loading frequency of 1.0 Hz,the compressive strength of the specimens reaches its maximum;furthermore,after a certain number of loading cycles,the sensitivity of compressive strength to loading conditions decreases.3)Consolidation confining pressure,cyclic stress ratio,and loading frequency all influence the dynamic elastic modulus of the specimens,which is characterized by a decrease in dynamic elastic modulus and a slowing rate of decrease with the accumulation of dynamic strain;for the same dynamic strain,the dynamic elastic modulus increases with the increase of consolidation confining pressure and loading frequency,while it decreases with the increase of cyclic stress ratio;under different conditions of consolidation confining pressure,loading frequency,and cyclic stress ratio,the inverse of the dynamic elastic modulus is approximately linearly correlated with dynamic strain.4)When the increment of dynamic strain is the same,the change in damping ratio decreases with the increase of consolidation confining pressure;it remains relatively constant and then decreases with the increase of cyclic stress ratio;and it decreases with the increase of loading frequency;the damping ratio fluctuates within a certain range and increases with the increase of dynamic strain.

Abstract:To promote the high-value utilization of agricultural solid waste in road engineering,a preparation and optimization process for corn straw fiber is proposed.Under the modification parameters of fibers with a mass ratio of NaOH to water of 4％,5％,and 6％,and cooking for 0.5,1.0,and 1.5 hours,as well as soaking for 0.5,1.0,and 1.5 hours,the synergistic effects of modification parameters on the oil absorption and heat resistance of the fibers are studied based on orthogonal experiments,range analysis,and variance analysis.Dynamic shear rheology and bending beam rheology tests are used to measure the high and low-temperature rheological properties of unmodified corn straw fibers,modified corn straw fibers,lignocellulosic fibers,and fiber-free asphalt mastic,verifying the technical feasibility of replacing lignocellulosic fibers with corn straw fibers.The results show that NaOH modification significantly increases the oil absorption rate of corn straw fibers and reduces their mass loss.The degree and significance of the influence of each modification parameter on fiber oil absorption and heat resistance are arranged in descending order as follows:cooking time,mass ratio of NaOH to water,and soaking time.The optimal modification process combination for corn straw fibers is a NaOH to water mass ratio of 6％,cooking for 1.5 hours,and soaking for 1.5 hours.Under the optimal modification conditions,the oil absorption rate of modified corn straw fibers increases by 1.54％compared to lignocellulosic fibers,and the mass loss decreases by 84.88％.The complex modulus,rutting factor,and creep rate of modified corn straw fiber asphalt mastic increase by 20.80％(48 ℃),21.95％(48℃),and 5.27％(-12℃),respectively,compared to lignocellulosic fiber asphalt mastic,with both having comparable stiffness moduli.Corn straw fibers used for asphalt modification provide both high-temperature stability and low-temperature crack resistance,making them a viable substitute for lignocellulosic fibers in asphalt pavement construction.

Abstract:To study the effect of aluminum ester modified mineral powder on the water stability performance of SBS modified AC-20C,limestone mineral powder is used as raw material,and aluminum ester served as the modifier.Aluminum ester modified limestone mineral powder is prepared using a chemical method,with oil absorption value and activation degree selected as evaluation indicators.An orthogonal experiment is conducted to explore the optimal modification process.The microstructural characteristics of ordinary mineral powder and aluminum ester modified mineral powder asphalt mastic are compared using fluorescence microscopy.Residual stability and freeze-thaw splitting strength tests are performed on the aluminum ester modified AC-20C specimens.The results show that the optimal modification conditions for aluminum ester modified mineral powder are a test temperature of 80 ℃,a mass fraction of aluminum ester mineral powder of 1.0％,and a modification time of 50 minutes.The activation degree of SBS modified AC-20C with aluminum ester modified mineral powder is 27.9 times that of ordinary mineral powder AC-20C,while the oil absorption value decreases by 58.7％.In terms of water stability performance,the residual stability of SBS modified AC-20C with aluminum ester modified mineral powder increases by 4.48％compared to ordinary mineral powder AC-20C,and the freeze-thaw splitting strength increases by 6.52％.Aluminum ester modified mineral powder can effectively improve the water stability performance against stripping of SBS modified AC-20C.

Abstract:To alleviate traffic congestion caused by urban road maintenance and improve traffic efficiency during maintenance operation,two typical urban road maintenance work zones in Fuzhou(single-lane closure and double-lane closure)are selected for analysis.Using video image recognition technology,vehicle operation data in the maintenance work zones are collected,and vehicle trajectories are extracted using Tracker software.Data processing and analysis is conducted with MATLAB and SPSS to examine the spatiotemporal distribution and speed characteristics of vehicles under maintenance scenarios,as well as the impact of maintenance work zone configurations on traffic flow.The results indicate that traffic volume in maintenance work zones varies significantly between off-peak and peak hours;after entering the warning area,vehicles shift from closed lanes to open lanes,with a marked decline in traffic efficiency during peak hours;vehicle speeds gradually decrease along the direction of traffic flow within maintenance work zones,with the lowest speeds and largest time headways observed in the activity area;in mandatory lane-changing behavior,the speed of the trailing vehicle in the target lane is a key factor influencing lane-changing decisions;in the two maintenance work zones,the proportions of lane-changing vehicles with higher speeds than those of the trailing vehicle are 65%and 71%,respectively;during peak hours,lane-changing initiation points are closer to the downstream end of the warning area,and the closer the lane-changing initiation point is to the activity area,the longer the lane-changing duration is.

Abstract:To promote high-quality development of commerce logistics and regional coordination,53 cities designated as national commerce-service logistics hubs are selected as sample cities.Based on panel data from these sample cities from 2014 to 2022,an evaluation index system is constructed with five dimensions:economic development level,commerce development level,infrastructure level,logistics development level,and talent-information potential.The entropy weighted-technique for order preference by similarity to ideal solution method is used to calculate comprehensive development level scores.A coupling coordination degree model is emplayed to quantify interactions and coordination among indicators,while the Dagum Gini coefficient is applied to analyze regional disparities.Results indicate that the average comprehensive development level of 53 sample cities increases steadily from 0.099 in 2014 to 0.156 in 2022,representing a cumulative increase of 57.58%,though the overall level remains low and requires improvement;the coupling coordination degree continuously improves,transitioning from mild imbalance to marginal imbalance,yet overall coordination stays suboptimal;regional disparities primarily stem from inter-regional differences,with an average annual contribution rate of 40.18%,making inter-regional gap reduction essential for curbing the expansion of overall disparities.

Abstract:To address the challenges of high transportation costs,elevated spoilage rates,and prominent carbon emissions in cold-chain logistics,this study develops a fresh-product cold-chain vehicle routing optimization model over a time-dependent road network,aiming to minimize total cost.The model jointly considers fixed vehicle usage cost,transportation cost,refrigeration cost,spoilage cost,carbon-emission cost,and time-window penalty cost.An improved African vulture optimization algorithm(AVOA)is proposed to solve the model by introducing an initialization strategy based on time-window centers and spatial savings,an adaptive parameter-control mechanism,and a multi-level local search strategy,while incorporating the global search strategy of the aquila optimizer.Computational experiments show that,when carbon emissions are considered,the improved AVOA reduces total cost by about 25.7%compared with the original AVOA and decreases the required fleet size from 9 to 7 vehicles.Furthermore,the total cost when accounting for carbon emissions is about 1.13%lower than when carbon emissions are not considered.The improved AVOA demonstrates markedly superior route-search capability over traditional algorithms,simultaneously optimizing distribution routes while internalizing carbon-emission costs to achieve both cost reduction and low-carbon delivery.The proposed approach provides an effective solution for cold-chain logistics routing.

Abstract:To enhance the accuracy of traffic accident severity prediction,an FHSPSO-RF model is developed,where foraging habitat selection particle swarm optimization(FHSPSO)is used to optimize key hyperparameters of a random forest(RF).Using traffic accident data from Seattle,Washington,from January 2022 to February 2023,twelve features are selected.The synthetic minority oversampling technique is applied to increase the samples of severe-injury and fatal crashes and improve class balance.The FHSPSO-RF model is compared with support vector machine(SVM),K-nearest neighbors(KNN),and logistic regression(LR).Shapley additive explanations(SHAP)are used to interpret how each feature influences severity.Results indicate that after oversampling,the recall of severe-injury and fatal crashes increases significantly,and the FHSPSO-RF model achieves more balanced overall performance.The model attains higher accuracy,precision,recall,and F1 score than the three benchmarks,yielding the best severity prediction.Across all crash types,the numbers of injuries and vehicles are the most influential drivers with significant positive effects on severity.The number of pedestrians,high-impact collision types such as head-on crashes,and complex road environments such as intersections and ramps form key risk combinations for severe-injury and fatal crashes.Property-damage-only crashes are closely related to whether a parked roadside vehicle is struck.The FHSPSO-RF model demonstrates strong predictive performance and interpretability,providing support for crash risk prediction and prevention-control decision making.

Abstract:To investigate the mechanical properties of the negative bending moment zone(NBMZ)at the pier top of a simply supported to continuous girder,the deformation coordination condition is taken as the continuous rotation angle at the pier top fulcrum.The analytical expression of the restraint bending moment in the NBMZ at the pier top is derived using bilinear method(BM)and age-adjusted effective modulus(AAEM)method.Theoretical analysis are carried out.The results of the proposed method are compared with that of the field experiments and Portland Cement Association(PCA)method and Construction Technology Laboratories(CTL)method.The research results indicate that the tensioning of prestressed reinforcement has the greatest impact on the negative bending moment zone at the pier top during the process of simple supported to continuous girder;The values of the proposed method are in good agreement with the measured experimental values and PCA method and CTL method.This indicates the proposed method BM-AAEM has the high accuracy,which can preliminarily estimate whether there is a risk of cracking in the NBMZ at the top of the pier.

Abstract:To systematically evaluate the ability of urban rail transit networks to withstand uncertain disruptions,this study takes the Shijiazhuang urban rail transit(planned)network as the research object.Based on complex network theory,an undirected and unweighted topology is constructed using the Space-L method.Network characteristics are identified by computing topological parameters such as degree distribution,average path length,and clustering coefficient.Six attack strategies covering node and edge failures are designed,and network resilience under random and targeted attacks is assessed using network efficiency and the proportion of the largest connected component.Critical nodes and edges are identified through sequential single-node and single-edge failure experiments.Results show that,compared with a corresponding random network,the Shijiazhuang(planned)network yields a small-world index of s=1.110 3>1.000 0,and its degree distribution approximately follows a Poisson distribution,indicating small-world properties.The network is sensitive to targeted attacks based on node degree and node betweenness,while it exhibits stronger robustness to attacks based on edge betweenness.The impacts of different node or edge failures on network efficiency vary markedly,and static topological indicators(degree,betweenness)are not in a simple positive correspondence with the actual performance degradation caused by their failures.Resilience should be enhanced by strengthening the protection of critical stations and track sections,optimizing the network topology,and establishing a multimodal emergency intermodal system.

Abstract:In the context of global warming and resource scarcity,promoting sustainable transportation is a vital component of the green transformation of socio-economic systems.Yet,no universal consensus has been reached on the definition of sustainable transportation,and systematic reviews of its current development remain limited.This paper provides a comprehensive review of both the conceptual foundation and the current state of sustainable transportation.First,it traces the historical evolution of the concept.Second,it synthesized and compared definitions proposed by international organizations and national or regional authorities.Sustainable transportation is herein defined as an innovative development model that minimizes environmental impacts,such as carbon emissions,air pollutants,and noise,reduces energy consumption,and integrates economic growth,social well-being,traffic safety,and equity,thereby preserving resources and opportunities for future generations.Third,the research priorities of 16 leading international and national institutions in the field are systematically reviewed.Finally,current progress summarized in terms of six key technological advances and four developmental models,with major challenges and issues identified.The findings provide theoretical insights and strategic guidance for the future advancement of sustainable transportation.

Abstract:To address the issues of high porosity and low resource utilization efficiency of steel slag,a micropore filling technology is proposed.Based on the principle of pneumatic driving,the gas-liquid replacement process within the pores of steel slag is optimized,allowing the cement slurry to be efficiently and stably injected into the micropores of the steel slag.The quality increment of the steel slag before and after filling is tested under different pressure application methods,pressure application times,water-cement ratios,experimental temperatures,and steel slag particle sizes,studying the impact of micropore filling technology on the porosity of steel slag.The results indicate that with an increase in pressure application time,the overall mass increment of the steel slag increases.Negative pressure filling offers both safety and efficiency advantages;at 4 minutes of pressure application,the mass increment of steel slag filled under negative pressure is 20%greater than that of positive pressure.The final filling quality of the two pressure application methods tends to be the same,approximately 0.45 g.The high viscosity and poor fluidity of the cement slurry cause the mass increment of the steel slag to initially decrease and then slightly increase as the water-cement ratio increases.When the water-cement ratio is 0.8,the mass increment of the steel slag is 4.5 times than that at a water-cement ratio of 2.0.Increasing the experimental temperature from 25 ℃ to 50 ℃ accelerates the hydration agglomeration of the cement,resulting in a 37.5%decrease in the mass increment of the steel slag and a significant reduction in filling efficiency.The filling effect is most pronounced when the steel slag particle size is>5-10 mm,with a mass increment of 0.16 g.By filling the pores of the steel slag with cement products,interfacial homogenization can be achieved,significantly reducing porosity and improving gas-liquid replacement efficiency.

Abstract:To accurately monitor the dynamic response of surrounding rock and support structures during tunnel construction and early operation phases,promptly identify potential instability risks,validate design rationality,and guide safe construction practices,systematic and high-precision on-site monitoring methods are implemented.Total station instruments are employed for continuous non-contact measurement of tunnel crown settlement,surrounding convergence,and surface settlement to precisely capture spatial deformation.Combined with geophysical radar for early detection of adverse geological formations ahead,automated data acquisition systems and specialized analysis software enable real-time transmission,processing,visualization,and early warning analysis of massive monitoring data.Post-excavation monitoring data indicate that the deformation of the surrounding rock after tunnel excavation follows a three-stage change pattern,transitioning from rapid change to slow change and finally to basic stability as construction progresses.This validates the applicability of the designed support parameters in most sections,but indicates insufficient support strength in specific weak surrounding rock sections.To address challenges including vulnerable monitoring points,significant construction interference,and humid dust environments,measures such as reinforcing protection points,optimizing workflows to reduce interference,selecting environment-resistant equipment,and enhancing calibration are adopted.A real-time monitoring system is established for dynamic analysis and early warning,ensuring data reliability and guiding construction safety.

Abstract:To study the degradation mechanism of the mechanical performance of the main girder of a prestressed concrete cable-stayed bridge under the action of vehicles and external factors,the cable-stays are equivalent to elastic supports.Using an equivalent three-span continuous beam as the basic structure,the analytical expressions for the degradation laws of cable force,bending moment,and deflection of the main girder after damage are derived.The research results indicate that after damage to the main girder,the cable force near the damaged area of the main girder increases;the changes in bending moment and deflection of the main girder primarily occur in the damaged span.Case studies validate the effectiveness of the theoretical calculation results on the degradation of the mechanical performance of the prestressed concrete cable-stayed bridge after damage to the main girder,which can be used for assessing the mechanical performance of the main girder after damage.

Abstract:To investigate the road performance of high modulus asphalt mixtures(HMAM)in long-life pavement applications,high boiling point petroleum is incorporated into base asphalt to prepare high modulus asphalt binder(HMAB).Penetration,softening point,brittleness point,and dynamic modulus tests are conducted to evaluate HMAB's hardness,high-temperature stability,low-temperature crack resistance,and dynamic load response characteristics,demonstrating its modulus enhancement and performance advantages over conventional binders.Furthermore,dynamic modulus,moisture susceptibility,rutting resistance,and fatigue tests are performed on HMAM to assess its structural stiffness,moisture resistance,high-temperature rutting resistance,and durability,confirming its suitability for long-life pavement compared to conventional mixtures.Results indicate that HMAB exhibits significantly higher stiffness than conventional asphalt while maintaining comparable low-temperature performance.Under high-temperature conditions,HMAM demonstrates a 50%higher dynamic modulus,approximately 10%improvement in moisture resistance,twice the resistance to permanent deformation,and 5～10 times greater fatigue cracking resistance compared to conventional mixtures.

Abstract:To enhance highway bus traffic safety and reduce accident rates,data from 2,320 samples are collected,including bus accident frequency,traffic volume,road characteristics,weather conditions,and holiday proportions,from three highways in eastern China.Accounting for accident heterogeneity,Poisson-lognormal(PLN),random parameters Poisson-lognormal(RP-PLN),and random effects Poisson-lognormal(RE-PLN)models are established.The Bayesian method and Markov chain Monte Carlo simulation estimate the posterior distribution of model parameters.The modeling results quantitatively assess the impact of various factors on highway bus accident frequency.Findings indicate that the RP-PLN model exhibits superior goodness-of-fit compared to the PLN and RE-PLN models.Road segment length,traffic volume,and holiday proportion show positive correlations with accident frequency,while temperature,relative humidity,and visibility demonstrate negative correlations.Holding other factors constant,a 1%increase in road segment length and traffic volume increases accident frequency by 0.90%and 0.62%,respectively.A one-unit increase in holiday proportion increases accident frequency by 8.30%.Conversely,a one-unit increase in temperature,relative humidity,and visibility reduces accident frequency by 5.72%,8.82%,and 6.55%,respectively.

Abstract:In order to analyze the extent of the influence of urban land use and road network morphology on interregional highway traffic accidents,33 towns along five highways(G503,G302,G334,G203,S514)in a northern city are selected as research subjects.The topology characteristic parameters are obtained by modeling the urban road network,and the intensity of land use and the degree of mixed land use are calculated using points of interest(POI).The random forest model is employed to analyze the influence of independent variables on interregional highway traffic accidents,and the correlation between independent variables and interregional highway traffic accidents is analyzed using negative binomial regression.The results indicate that the feature importances for the number of POIs,betweenness centrality of the interregional highways,degree of the interregional highways,number of urban nodes,and degree of mixed land use in the random forest model are 0.62,0.14,0.11,0.07,and 0.06,respectively.The number of POIs has the greatest influence on interregional highway traffic accidents,while betweenness centrality and the number of nodes of the interregional highways have some influence.The number of urban nodes and the degree of mixed land use have weaker influence on interregional highway traffic accidents.In the negative binomial regression method,the betweenness centrality of the interregional highways and the number of POIs are significantly and positively associated with interregional highway traffic accidents,while the number of urban nodes,degree of the interregional highways,and degree of mixed land use are not significantly correlated.The conclusions of the random forest model are close to those of the negative binomial regression analysis.The random forest model adapts well to the non-additive and non-linear characteristics of the independent variables and is suitable in analyzing the causes of traffic accidents.Controlling urban scale and reasonably planning urban road networks are of great significance in reducing the risk of interregional highway traffic accidents and improving traffic safety.