Research Article
A Crash Severity Prediction Method Based on Improved Neural Network and Factor Analysis
Table 5
Summary of FII expectation (Kā=ā100) and relative percentage for two different methods.
| Variables | Category | NN with PSO () | NN with PSO () | FII | Relative percentage (%) | FII | Relative percentage (%) |
| Acctype | Nonroad | 0.108 | 77.3 | 0.080 | 63.4 | Month | Nonroad | 0.088 | 63.1 | 0.102 | 81.0 | Weekday | Nonroad | 0.061 | 43.7 | 0.054 | 43.5 | loc_type | Nonroad | 0.080 | 57.1 | 0.076 | 60.1 | rd_char1 | Road | 0.078 | 55.6 | 0.063 | 50.2 | Rdsurf | Road | 0.052 | 37.4 | 0.456 | 36.2 | Light | Nonroad | 0.069 | 49.1 | 0.071 | 56.1 | Weather | Nonroad | 0.067 | 47.7 | 0.059 | 47.2 | func_cls | Road | 0.063 | 45.1 | 0.058 | 46.1 | drv_sex | Nonroad | 0.024 | 17.4 | 0.017 | 13.1 | drv_rest | Nonroad | 0.043 | 30.5 | 0.039 | 31.0 | Vehtype | Nonroad | 0.092 | 65.6 | 0.090 | 72.0 | dir_curv | Road | 0.032 | 23.2 | 0.028 | 22.1 | dir_grad | Road | 0.020 | 14.2 | 0.019 | 15.1 | drv_age | Nonroad | 0.117 | 83.4 | 0.113 | 90.0 | Vehyr | Nonroad | 0.140 | 100.0 | 0.126 | 100 | curv_ang | Road | 0.047 | 33.5 | 0.045 | 35.4 | pct_grad | Road | 0.056 | 40.1 | 0.052 | 41.3 | deg_curv | Road | 0.035 | 25.1 | 0.032 | 25.4 | curv_rad | Road | 0.040 | 28.4 | 0.034 | 26.8 |
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