Benefit

Advanced weigh stations with preclearance systems have benefit-to-cost ratios ranging from 8.9:1 to 12.8:1.

Benefit-to-cost analyses were performed to help with decision making regarding future upgrades, enhancements, and maintenance for weigh stations in Michigan.


03/30/2015
Michigan; United States


Summary Information

The primary goal of this study was to determine the benefits of the existing fixed weigh stations in Michigan, the cost of upgrading, enhancing and maintaining these weigh stations, and the cost of using alternative solutions (e.g. mobile enforcement) in place of fixed weigh stations or as an enhancement to it. Benefit-cost analyses were performed to help the Michigan Department of Transportation (MDOT) and the Michigan State Police (MSP) in decision making on future commercial vehicle enforcement strategies. To conduct a benefit-cost analysis, specific data on cost and benefit components were derived for each alternative strategy. The cost components included construction/installation/upgrade costs, operating costs, labor costs, and maintenance costs. Additional travel time for commercial vehicles entering a fixed weigh station (including the use of bypass lane triggered by the low-speed WIM) was also considered. The benefit components considered included pavement cost saving associated with commercial vehicle enforcement, as well as savings associated with safety and travel time. The conventional benefit-cost ratio (BCR) approach was adopted in determining economic worthiness of each strategy.

Fixed weigh stations were grouped into four levels (basic, intermediate, advanced and most advanced) depending on what features were present. In general:
  • The basic fixed weigh station consisted of just a static scale
  • The intermediate level weigh station had a mainline Weigh-in-Motion (WIM) present
  • The advanced level fixed weigh station had a low-speed WIM and bypass lane present
  • The most advanced fixed weigh station had a preclearance system.


RESULTS

The table below presents the BCR results for adding low-speed WIM and bypass lane in addition to preclearance system. Note that for basic fixed weigh stations this option includes adding a mainline WIM. The results show a comparison of the BCRs for existing condition and upgraded condition. This study also evaluated the potential to replace existing fixed weigh stations with advanced mobile enforcement. The advanced mobile enforcement approach incorporates roadside technologies necessary for identifying commercial vehicles. An average of two trucks per hour was used to estimate the benefits and costs of this approach. Assuming that the mobile enforcement is conducted for the same amount of time as the existing fixed weigh station, the benefits and costs were estimated.

Benefit-cost analysis results for individual fixed weigh stations

Fixed Weigh Station Highway Current Level Current BCR Advanced BCR Most Advanced BCR Mobile Enforcement BCR
New Buffalo_EB I-94 EB Most Advanced
12.77
N/A
12.77
.80
Monroe_NB I-75 NB Most Advanced
8.86
N/A
8.86
.39
New Buffalo_WB I-94 WB Advanced
10.09
10.09
10.22
.66
Monroe_SB I-75 SB Advanced
8.91
8.91
9.61
.37
Grass Lake_EB I-94 EB Advanced
4.00
4.00
4.24
.14
Grass Lake_WB I-94 WB Advanced
4.11
4.11
4.24
.14
Coldwater_NB I-69 NB Advanced
1.94
1.94
1.73
.18
Ionia_WB I-96 WB Intermediate
-0.84
2.01
1.99
.21
Ionia_EB I-96 EB Intermediate
-0.84
2.01
1.99
.21
Fowlerville_EB I-96 EB Intermediate
-0.30
1.46
1.49
.18
Fowlerville_WB I-96 WB Intermediate
-0.30
1.46
1.49
.18
Powers US-41 & US-2 Basic
1.48
N/A
N/A
.43
Pontiac_SB I-75 SB Basic
-0.31
1.14
0.41
.18
Telegraph US-24 NB & SB Basic
0.00
N/A
N/A
.01
Cambridge M-50 & US-12 Basic
0.33
N/A
N/A
.05

Analysis of the 15 existing fixed weigh stations indicated that:
  • The two most advanced fixed weigh stations (Monroe NB and New Buffalo EB) are economically beneficial (with BCR values of 8.86 and 12.77, respectively). This can be attributed to their ability to focus on potential violators while allowing compliant trucks to bypass the fixed weigh station, either through mainline (if subscribed to PrePass, or through a bypass lane if detected to comply with regulations).
  • All advanced level fixed weigh stations (New Buffalo WB, Monroe SB, Grass Lake EB, Grass Lake WB, and Coldwater) are economically beneficial with BCR values greater than 1.00. However, it should be noted that Monroe SB and New Buffalo WB catch violators who are leaving the state of Michigan.
  • Intermediate fixed weigh stations at Fowlerville and Ionia may be generating greater disbenefits due to their inability to handle the truck volume present with their current configuration which requires all trucks to enter the fixed weigh station. Further analysis on whether revising the number of hours the stations are open can improve their benefits revealed that they will still be uneconomical regardless of changes in the schedule.
  • All basic fixed weigh stations (except Powers) were found to be uneconomical with BCR values of less than 1.00. Powers, the only fixed weigh station in the Upper Peninsula, is one of the most isolated fixed weigh stations such that an overweight truck caught at this station would have potentially travelled a longer stretch of highway before being caught, hence damaging more pavement. Similar to the intermediate level, further analysis on whether revising the operation schedule can improve their benefits revealed that they will still be uneconomical regardless of changes in the schedule.
  • Upgrading of current intermediate fixed weigh stations (Ionia and Fowlerville) and one basic fixed weigh station (Pontiac) to the advanced level improved their performance significantly and made them economically beneficial (with new BCR values ranging from 1.14 – 2.01)
  • The decline of BCR at Coldwater can be explained by the fact that adding the preclearance system will add installation and maintenance costs while not significantly changing the number of violators caught.
  • As seen in the table, advanced mobile enforcement is not a feasible strategy to replace fixed weigh stations in Michigan. The low BCR values are the results of relatively lower capture rate by one officer conducting mobile enforcement compared to one officer when stationed at a fixed weigh station. This suggests that mobile enforcement needs to be a supplemental strategy, combined with fixed static scale by focusing on potential bypass routes to increase visibility of police officers and deter potential bypassing problem.

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Source

Evaluating Michigan Commercial Vehicle Enforcement Strategies and Facilities

Author: Kwigizile,Valerian; Jun-Seok Oh; Fathi Alkhatni; Randy Jorge (Western Michigan University); Andrew Ceifetz; Joyce Yassin (Opus International Consultants)

Published By: Michigan DOT

Source Date: 03/30/2015

Other Reference Number: Report No. RC 1622

URL: https://rosap.ntl.bts.gov/view/dot/28753

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Goal Areas

Productivity

Typical Deployment Locations

Statewide

Keywords

weigh-in-motion, WIM

Benefit ID: 2017-01142