To improve the spatial coverage and timeliness of expressway traffic state estimation, this paper proposes a joint state estimation method that integrates observational data with a traffic flow model based on the Kalman filter. Intelligent Connected Vehicle (ICV) probe data are used as observational inputs. Based on Cooperative Adaptive Cruise Control (CACC) and the Intelligent Driver Model (IDM), the motion behaviors of ICV and human-driven vehicles in mixed traffic flow are simulated, and traffic density is estimated using the Cell Transmission Model (CTM). Validation using SUMO simulations and NGSIM field data shows that the estimation error of the proposed method decreases significantly as the ICV penetration rate increases. Specifically, the Mean Absolute Percentage Error (MAPE) is below 20% at a 20% penetration rate; the estimation accuracy improves further at 40%; and when the penetration rate reaches 80%, the MAPE is reduced by 16.54% compared with statistical estimation methods. The proposed method achieves high estimation accuracy and robustness, which is suitable for traffic state estimation in complex traffic environments.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |