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Evaluation of Single Lane Parallel-Type Entrance Ramp Terminal Using Vehicle Dynamics Model for Freeways

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Figure 1.

Typical Single-Lane Entrance Ramps: A. Tapered Design. B. Parallel Design (AASHTO 2018)
Typical Single-Lane Entrance Ramps: A. Tapered Design. B. Parallel Design (AASHTO 2018)

Figure 2.

Specifications of 108 kg/kW truck
Specifications of 108 kg/kW truck

Figure 3.

Longitudinal speed versus station for 61 kg/kW truck
Longitudinal speed versus station for 61 kg/kW truck

Figure 4.

Longitudinal speed versus station for 108 kg/kW truck
Longitudinal speed versus station for 108 kg/kW truck

Figure 5.

Acceleration lane lengths at level grade
Acceleration lane lengths at level grade

Figure 6.

Acceleration lane lengths at a 3% downgrade
Acceleration lane lengths at a 3% downgrade

Figure 7.

Acceleration lane lengths at a 5% downgrade
Acceleration lane lengths at a 5% downgrade

Figure 8.

Speeds at the end of the acceleration lane at level grade
Speeds at the end of the acceleration lane at level grade

Figure 9.

Acceleration rate for 61 kg/kW truck
Acceleration rate for 61 kg/kW truck

Figure 10.

Acceleration rates for 61 kg/kW truck at different grades
Acceleration rates for 61 kg/kW truck at different grades

Figure 11.

Histogram and PP plots of remainders for the fitted model
Histogram and PP plots of remainders for the fitted model

Acceleration lane length at a 5% downgrade

Design Speed, V (km/h) Merge Speed, Va (km/h) Initial Speed V(km/h)
40 50 60
Weight to Power Ratio (kg/kW)
61 67 86 108 61 67 86 108 61 67 86 108
Acceleration Lane Length (m)
100 74 189 196 207 230 155 160 168 186 108 111 118 128
120 88 323 334 340 377 277 285 299 334 230 238 249 276
130 92 360 372 379 424 315 326 340 380 271 279 290 322

Acceleration lane length at a 5% upgrade

Design Speed, V (km/h) Merge Speed, Va (km/h) Initial Speed V(km/h)
40 50 60
Weight to Power Ratio (kg/kW)
61 67 86 108 61 67 86 108 61 67 86 108
Acceleration Lane Length (m)
100 74 1036 1863 NA NA 919 1763 NA NA 727 1575 NA NA
120 88 NA NA NA NA NA NA NA NA NA NA NA NA
130 92 NA NA NA NA NA NA NA NA NA NA NA NA

Acceleration lane length at a 3% downgrade

Design Speed, V (km/h) Merge Speed, Va (km/h) Initial Speed V(km/h)
40 50 60
Weight to Power Ratio (kg/kW)
61 67 86 108 61 67 86 108 61 67 86 108
Acceleration Lane Length (m)
100 74 221 233 271 295 182 191 206 237 127 134 145 163
120 88 388 404 425 490 335 351 378 438 280 293 315 364
130 92 435 454 478 553 397 402 432 501 332 343 369 428

Acceleration lane length at level grade

Design Speed, V (km/h) Merge Speed, Va (km/h) Initial Speed V(km/h)
40 50 60
Weight to Power Ratio (kg/kW)
61 67 86 108 61 67 86 108 61 67 86 108
Acceleration Lane Length (m)
100 74 337 334 390 492 272 286 325 407 205 205 224 268
120 88 620 649 741 933 537 568 651 844 450 475 547 708
130 92 701 736 848 1087 619 661 775 1002 556 584 659 871

Acceleration lane length at a 3% upgrade

Design Speed, V (km/h) Merge Speed, Va (km/h) Initial Speed V(km/h)
40 50 60
Weight to Power Ratio (kg/kW)
61 67 86 108 61 67 86 108 61 67 86 108
Acceleration Lane Length (m)
100 74 547 630 958 NA 478 520 824 NA 358 430 754 NA
120 88 1247 1582 NA NA 1181 1471 NA NA 995 1300 NA NA
130 92 1595 NA NA NA 1490 NA NA NA 1362 NA NA NA

Acceleration lane lengths from reviewed sources and proposed acceleration lane lengths from this study

AASHTO Green Book 2018 NCHRP Rept. 505- 2003 This study (108 kg/kW) Difference Between AASHTO and This Study
Methods Experimental TSPM TruckSim -
Assumed Initial Speed (km/h) 35 35 35 -
Assumed Merge Speed (km/h) 74 285 530 526 241
88 490 994 983 493

Minimum acceleration lane length [1]

Acceleration Lane Length (m) For Design Speed of Controlling Feature on Ramp V’ (km/h), V’(km/h)
40 50 60
Design Speed, V (km/h) Merge Speed, Va (km/h) Average Running Speed at Controlling Feature on Ramp V’a (km/h)
35 42 51
100 74 285 255 205
120 88 490 460 410
130 92 530 520 500

Adjusted Grade Factors [1]

Design Speed, V (km/h) Ratio of Length on Grade to Length on Level for Design Speed of Turning Curve (km/h)
40 50 60 All Speeds
3 to 4% Upgrade 3 to 4% Downgrade
100 1.5 1.6 1.7 0.6
120 1.5 1.6 1.7 0.6
130 1.6 1.7 1.8 0.6
5 to 6% Upgrade 5 to 6% Downgrade
100 1.7 1.9 2.2 0.5
120 2.15 2.35 2.8 0.5
130 2.3 2.5 3 0.5

Results in assumption 4

Variable Tolerance VIF
Grade 0.902 1.109
Weight to Power ratio 0.941 1.063
Merge Speed to Initial Speed 0.759 1.318

Comparison of acceleration rate in the AASHTO and this study

Design Speed (km/h) Merge Speed (km/h) Design Speed (km/h)
40 50 60
Initial Speed (km/h)
35 42 51
Acceleration Rate for 108 kg/kW Truck at Level Grade (km/h/s)
Acceleration Rate (Green book AASHTO) Acceleration Rate (TruckSim) Acceleration Rate (Green book AASHTO) Acceleration Rate (TruckSim) Acceleration Rate (Green book AASHTO) Acceleration Rate (TruckSim)
100 74 2.01 2.38 2.00 1.94 1.94 1.58
120 88 1.91 2.38 1.84 1.94 1.78 1.58

Compares maximum weight to power ratios for minimum acceleration length in NCHRP505 and this study at upgrades

Design Speed (km/h) Merge Speed (km/h) Design Speed (km/h)
40 50 60
Initial Speed (km/h)
35 42 51
Maximum weight to power ratios (kg/kW) at 2% and 3% upgrades
NCHRP 505 (TSPM) This Study (TruckSim) NCHRP 505 (TSPM) This Study (TruckSim) NCHRP 505 (TSPM) This Study (TruckSim)
100 74 52 - 52 - 52 61
120 88 49 - 49 - 49 -

Speeds at the end of the acceleration lane at level grade

Design Speed, V (km/h) Merge Speed, Va (km/h) Initial Speed V(km/h)
40 50 60
Weight to Power Ratio (kg/kW)
61 67 86 108 61 67 86 108 61 67 86 108
Acceleration Lane Length (m)
100 74 70 70 69 64 73 72 70 68 74 74 73 71
120 88 82 81 78 74 84 83 81 76 86 85 82 80
130 92 83 82 80 76 87 86 82 79 89 88 86 82

Specifications of trucks

Parameters Tractor Load Tractor Load Tractor Load Tractor Load
61 kg/kW Truck 67 kg/kW Truck 86 kg/kW Truck 108 kg/kW Truck
Length (mm) - 3000 - 3000 - 4500 - 7500
Width (mm) 2438 1000 2438 1000 2438 1750 2438 2000
Height (mm) 3200 1000 3200 1000 3200 1800 3200 2000
Height of mass center (mm) 1175 1350 1175 1350 1020 2150 1175 2300
Total Mass (kg) 14165 4000 14165 6000 8525 20000 14165 18340
Powertrain (kw) 300 - 300 - 330 - 300 -

Acceleration rates for 61 kg/kW truck at different grades

Design Speed (km/h) Merge Speed (km/h) Initial Speed (km/h)
40 50 60
Acceleration Rate for 61 kg/kW Truck at Level Grade (km/h/s)
100 74 3.46 2.83 2.10
120 88 3.46 2.81 2.30
130 92 3.46 2.81 2.30

Comparison of maximum weight to power ratios for minimum acceleration length in NCHRP505 and this study

Design Speed (km/h) Merge Speed (km/h) Design Speed (km/h)
40 50 60
Initial Speed (km/h)
35 42 51
Maximum weight to power ratios (kg/kW) at level grade
NCHRP 505 (TSPM) This Study (TruckSim) NCHRP 505 (TSPM) This Study (TruckSim) NCHRP 505 (TSPM) This Study (TruckSim)
100 74 70 67 67 67 70 67
120 88 61 - 64 - 64 -
eISSN:
2720-6947
Langue:
Anglais
Périodicité:
4 fois par an
Sujets de la revue:
Architecture and Design, Architecture, Architects, Buildings