Work Zone Road User Costs - Concepts and Applications

Appendix A. Kepner-Tregoe Decision Analysis Worksheet for MOT Strategy Selection

Project Information

Facility Name – US 00 Pavement Reconstruction

Facility Type – Arterial

Project Number – # A600000

Route & Milepost – US 00, MP 100 to 105

District/County – District 1, Polk County

By – H. Miller

Date – 05/05/2005

Step 1 - Prepare Decision Statement

To identify the most appropriate strategy for maintaining traffic on US 00 during the reconstruction of the pavement segments between mileposts 100 and 105.

Step 2A – Define MUST Objectives

List the mandatory attributes of a preferred MOT strategy for this project.

Mandatory attributes for a preferred MOT strategy.

Performance Measure/Criteria	Go/No Go
Maintain a minimum of one lane each direction for work zone traffic on weekdays
No lane closure from 7 a.m. to 10 a.m. and 4 p.m. to 8 p.m. on weekdays
Queue length not more than 0.75 for more than 1 hour
Delay time not more than 30 minutes
Available detour routes exceed capacity?
MOT alternative has no constructability issues

Step 2B & 3 – Define & Weight WANT Objectives

List the desired attributes of a preferred MOT strategy for this project. Assign weights to each attribute based on their relative importance on a scale of 1 to 10, with 1 indicating “least preferable” and 10 indicating “most preferable” or “equally preferable.”

Desired attributes and assigned weights.

Performance Measure/Criteria	Weight
Delay costs ($)	10
Vehicle operating costs	8
Number of days for project completion	10
Traffic control & associated construction costs ($)	8
Average time to clear a non-injury incidence (min.)	4
Maintenance of emergency services (adjectival ratings – poor, average, good)	6
Environmental impacts (adjectival ratings – low, moderate, severe)	3

Step 4 – Identify Candidate MOT Alternatives

Identify and list the candidate MOT alternatives for considered in the decision analysis.

Candidate MOT alternatives.

Alternative	Description
A	Daytime partial lane closure –closed between 7 a.m. to 5 p.m
B	Nighttime partial lane closure –closed between 8 p.m. to 6 a.m.
C	Nighttime partial lane closure –closed between 9 p.m. to 7 a.m.
D	Nighttime full lane closure –closed between 9 p.m. to 7 a.m.
E	Truck traffic diverted through detour routes during peak hours.

Step 5 – Conduct Work Zone Impact Assessment and Summarize Findings

Summarize the findings of the work zone impact assessment.

Summary of the Work Zone impact assessment.

Performance Measure/Criteria	A	B	C	D	E
Maintain a minimum of 1 lane each direction for WZ traffic during weekdays	No	Yes	Yes	Yes	Yes
No lane closure between 7a.m. through 10 a.m. and 4 p.m. through 8 p.m. during weekdays	No	Yes	Yes	Yes	Yes
MOT alternative has no constructability issues	No	No	No	No	No
Average delay time per vehicle (min)	19.0	6.0	3.0	10.0*	20.0**
Maximum queue length (mi.)	1.6	0.0	0.0	0.5*	0.5**
Available detour route exceed capacity?	No	No	No	No	Yes
Average time to clear a non-injury incidence (min.)	20	25	25	15	10
Delay costs	$5,300	$3,125	$2,800	$4,700	$6,800
Vehicle operating costs	$1,484	$656	$728	$1,175	$1,836
Traffic control & associated construction costs	$55,000	$94,000	$75,000	$109,000	$85,000
Number of days for project completion	150	84	84	60	90
Maintenance of emergency services	moderate	moderate	moderate	good	good
Environmental impacts	moderate	severe	severe	low	low

Step 6 – Evaluate Alternatives against MUST Objectives

Evaluate each alternative against the MUST objectives and check whether the attributes of an alternative satisfy all of the MUST requirements. Use the findings of the impact assessment summarized in Step 5. Assign Go or No Go outcome based on your evaluation indicating your decision to retain or eliminate an alternative for the next step. Any alternative with a No Go outcome will be eliminated from further evaluation.

Alternatives evaluation against MUST objectives.

Performance Measure/Criteria	A	B	C	D	E
Maintain a minimum of 1 lane each direction for WZ traffic during weekdays	Go	Go	Go	Go	Go
No lane closure between 7a.m. through 10 a.m. and 4 p.m. through 8 p.m. during weekdays	Go	Go	Go	Go	Go
Queue length not more than 0.75 for more than 1 hour	No Go	Go	Go	Go	Go
Delay time not more than 30 minutes	No Go	Go	Go	Go	Go
Alternative detour route exceeds capacity?	Go	Go	Go	Go	No Go
Alternative has no constructability constraints	Go	Go	Go	Go	Go

Step 7 – Evaluate Alternatives against WANT Objectives

Evaluate each alternative against the WANT objectives based on the findings of the impact assessment summarized in Step 5. Assign scores to each alternative against the listed objectives indicating how well the alternative meets that objective. Use a scale of 1 to 10, with a score of 1 indicating “least preferable” and 10 indicating “most preferable” or “equally preferable.”

Alternatives evaluation against WANT objectives.

Performance Measure/Criteria	Alternative Score
	A	B	C	D	E
Delay costs ($)		9	10	6
Vehicle operating costs		10	8	7
Number of days for project completion		7	7	10
Traffic control & associated construction costs ($)		8	8	10
Average time to clear a non-injury incidence (min.)		6	6	10
Maintenance of emergency services (adjectival ratings – poor, average, good)		6	6	10
Environmental impacts (adjectival ratings – low, moderate, severe)		3	3	10

Step 8 – Calculate the Weighted Scores of Alternatives

Calculate the weighted scores by multiplying the alternative score (Step 7) with the corresponding objective weights (Step 2B) to determine the relative performance of the alternatives. Calculate the total weighted score for each alternative. Indicate the alternative with the highest total score as the tentative choice.

Weighted scores of alternatives.

Performance Measure/Criteria	Alternative Score
	A	B	C	D	E
Delay costs ($)		90	100	60
Vehicle operating costs		80	64	56
Number of days for project completion		70	70	100
Traffic control & associated construction costs ($)		64	64	80
Average time to clear a non-injury incidence (min.)		24	24	40
Maintenance of emergency services (adjectival ratings – poor, average, good)		36	36	60
Environmental impacts (adjectival ratings – low, moderate, severe)		9	9	30
Total weighted score		373	367	426

Tentative choice: Alternative D

Step 9 – Evaluate of Adverse Consequences (optional)

Identify the potential risk factors and list under the “Adverse Consequences” column. Indicate the probability of the event under “Pr” column for each alternative on a scale from “Low” to “High,” with a rating of “Low” indicating “an unlikely event” and “High” indicating “a most probable event.” Indicate the severity of the event under “Sr” column for each alternative on a similar scale, with a value of “Low” indicating “inconsequential” and “High” indicating “very severe.” Identify “high-risk” and “low-risk” alternatives.

Adverse consequences.

Adverse Consequences	B		C		D
	Pr	Sv	Pr	Sv	Pr	Sv
Flood impact	Low-medium	HM	Low-medium	HM	Low-medium	High-medium
High severity crashes	High-medium	Low	High-medium	Low	High-medium	Low-medium
Emergency evacuation	High-medium	Low	High-medium	Low	High-medium	High

High-risk choice: Alternative D

Low-risk choice: Alternatives B and C

Step 10 – Select the Preferred MOT Strategy

Summarize the total weighted score (from Step 8) as well as the risk score (from Step 9) for each alternative and rank them.

Preferred MOT strategy.

Alternative	Description	Weighted Score	Risk Score	Rank
A	Daytime partial lane closure –closed between 7 a.m. to 5 p.m	Eliminated	Eliminated	Eliminated
B	Nighttime partial lane closure –closed between 8 p.m. to 6 a.m.	373	Low-risk	1
C	Nighttime partial lane closure –closed between 9 p.m. to 7 a.m.	367	Low-risk	2
D	Nighttime full lane closure –closed between 9 p.m. to 7 a.m.	426	High-risk	Eliminated
E	Truck traffic diverted through detour routes during peak hours.	Eliminated	Eliminated	Eliminated

Result

Indicate the preferred MOT strategy from Step 9.

Result.

Alternative	Description
B	Nighttime partial lane closure –closed between 8 p.m. to 6 a.m.

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