Capital costs to install temporary Variable Speed Limit (VSL) systems in Texas ranged from $91K to $180K.

Experience planning, installing, and evaluating pilot Variable Speed Limit (VSL) systems in Texas.

Made Public Date
05/25/2017

28

San Antonio
Texas
United States

287

Temple
Texas
United States

288

Eastland County
Texas
United States
Identifier
2016-00365
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Summary Information

In 2014, acting on a ruling by the Texas Transportation Commission, TxDOT and Texas A&M Transportation Institute (TTI) a Variable Speed Limit (VSL) pilot program was implemented. The pilot program aimed to study the effectiveness of temporarily lowering speed limits to address inclement weather, congestion, road construction, and other factors that can affect the safe and orderly movement of freeway traffic.

The VSL systems were implemented in the summer of 2014 to assess performance under a variety of operational conditions:

  • Urban Congestion Site: San Antonio, SL 1604SL 1604 WB, US 281 to IH-10. Data collected from June 30, 2014 – December 31, 2014.
  • Construction Work Zone Site: Temple, IH-35 NB, MM 297 to MM 301. Data collected from June 23, 2014 – November 30, 2014.
  • Weather-Related Site: Ranger Hill, Eastland County, IH-20 EB and WB. Data collected from July 21, 2014 – January 30, 2015.

The project team developed detailed cost estimates at each deployment site. Costs estimates covered Portable Changeable Message Sign (PCMS) rentals and modifications required to integrated equipment to the PCMS, radar sensors, visibility sensors, roadway condition sensors, modems, and other miscellaneous equipment. All of these costs were calculated with indirect costs applied where assumed.

Total Equipment Initial Cost Estimate

Site
Direction
Site Cost ($)
San Antonio
WB
180,487
Temple
NB
116,187
Ranger Hill, Eastland County
EB
108,503
Ranger Hill, Eastland County
WB
91,464
Total Equipment Cost
496,641


Initial Cost Estimates for WB SL 1604 VSL Site, San Antonio.

Equipment
Quantity
Payment Unit
Unit Cost ($)
Monthly Cost ($)
Total Cost($)
Reduced Speed Ahead PCMS
1
Monthly
3,227
3,227
12,908
VSL PCMS—Base
8
Monthly
2,708
21,664
86,656
VSL PCMS—Modifications
8
Monthly
519
4,152
16,608
Vehicle Detector
8
Each
5,500
N/A
44,000
Roadway Visibility Sensor
0
Each
5,224
N/A
Roadway Condition Sensor
1
Each
11,315
N/A
11,315
Vehicle Detector Modem
8
Each
500
N/A
4,000
Miscellaneous
1
Each
5,000
N/A
5,000
Total Equipment Costs
$180,487


Initial Cost Estimates for NB IH-35 VSL Site, Temple.

Equipment
Quantity
Payment Unit
Unit Cost ($)
Monthly Cost ($)
Total Cost($)
Reduced Speed Ahead PCMS
1
Monthly
2,708
2,708
10,832
VSL PCMS—Base
5
Monthly
2,708
13,540
54,160
VSL PCMS—Modifications
5
Monthly
519
2,595
10,380
Vehicle Detector
4
Each
5,500
N/A
22,000
Roadway Visibility Sensor
0
Each
5,224
N/A
Roadway Condition Sensor
1
Each
11,315
N/A
11,315
Vehicle Detector Modem
5
Each
500
N/A
2,500
Miscellaneous
1
Each
5,000
N/A
5,000
Total Equipment Costs
$116,187


Initial Cost Estimates for EB IH-20 VSL Site, Ranger Hill, Eastland County.

Equipment
Quantity
Payment Unit
Unit Cost ($)
Monthly Cost ($)
Total Cost($)
Reduced Speed Ahead PCMS
1
Monthly
2,708
2,708
10,832
VSL PCMS—Base
4
Monthly
2,708
10,832
43,328
VSL PCMS—Modifications
4
Monthly
519
2,076
8,304
Vehicle Detector
4
Each
5,500
N/A
22,000
Roadway Visibility Sensor
1
Each
5,224
N/A
5,224
Roadway Condition Sensor
1
Each
11,315
N/A
11,315
Vehicle Detector Modem
5
Each
500
N/A
2,500
Miscellaneous
1
Each
5,000
N/A
5,000
Total Equipment Costs
$108,503


Initial Cost Estimates for WB IH-20 VSL Site, Ranger Hill, Eastland County.

Equipment
Quantity
Payment Unit
Unit Cost ($)
Monthly Cost ($)
Total Cost($)
Reduced Speed Ahead PCMS
1
Monthly
2,708
2,708
10,832
VSL PCMS—Base
4
Monthly
2,708
10,832
43,328
VSL PCMS—Modifications
4
Monthly
519
2,076
8,304
Vehicle Detector
4
Each
5,500
N/A
22,000
Roadway Visibility Sensor
1
Each
5,224
N/A
Roadway Condition Sensor
1
Each
11,315
N/A
Vehicle Detector Modem
5
Each
500
N/A
2,000
Miscellaneous
1
Each
5,000
N/A
5,000
Total Equipment Costs
$91,464
System Cost

Four VSL System configurations: $180,487; $116,187; $108,503; and $91,464.

System Cost Subsystem