Fig 1.
(a) Road alignment. (b) Road superelevation.
Fig 2.
Distribution of road alignment indicators.
(a) Radius (R) of circular curve (m). (b) Grade (t), vertical rise/slope length (%).
Table 1.
Simulation parameters of vehicle.
Table 2.
Classification standards for expressway alignment analysis units.
Fig 3.
Target curves and actual value of the vehicle operating speed.
Table 3.
Model parameter of MOVES.
Fig 4.
VSP variation curve.
Fig 5.
VSP distribution patterns.
Fig 6.
Spatial distribution of VSP from the (a) LDV and (b) HDV. HC, horizontal curve; CS, curve–slope combination; S, straight; SS, short straight; LS, longitudinal slope.
Table 4.
Normality test for VSP mean value distribution of different alignment units.
Fig 7.
Box plots of VSP spatial distribution of the (a) LDV and (b) HDV.
Table 5.
Carbon emission equivalent value per second.
Fig 8.
Correlation between VSP and carbon emissions from the (a) LDV and (b) HDV.
Table 6.
Total carbon emissions.
Table 7.
Relevant real-vehicle emission test data.
Fig 9.
Carbon emission per kilometer at each alignment unit of the (a) LDV and (b) HDV.
Table 8.
Correlation degree between carbon emissions per kilometer and various factors.
Fig 10.
Monthly average temperature and humidity at different altitudes.
Data are the average monthly temperature and humidity values for each month in recent 10 years and were obtained from the China Weather website, http://www.weather.com.cn/.
Table 9.
Average speed distribution conditions of MOVES county scale model.
Fig 11.
Monthly carbon emission change curve at different altitudes of the (a) LDV and (b) HDV. st, average number of vehicle starts.