CHAPTER 11 PAVEMENT TYPE DETERMINATION 11.1 PAVEMENT … · 2013. 4. 3. · Publication 242,...

Publication 242, Chapter 11 SOL 482-13-XX Attachment

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CHAPTER 11

PAVEMENT TYPE DETERMINATION

11.1 PAVEMENT TYPE SELECTION FACTORS

A highway system designation shall not determine the choice of pavement type. The

following factors should be considered when choosing a pavement type:

Economics – Pavement type determination can be influenced by the results of an Engineering

Economic analysis (e.g., a Life-Cycle Cost Analysis) on the cost of construction and future

maintenance.

Alternate Bidding – Pavement type may be determined through Alternate Bidding as described

in Section 11.6.

Performance of Similar Pavement in the Area – Knowing how a particular design type

performed in the past is a valuable guide in predicting future performance. However, there must

be a good correlation between conditions and service requirements of the reference pavements

and the designs under study. Caution is urged against relying on performance records of

reference pavements subjected to much lighter loadings for a large portion of their service life.

Caution is also urged when considering the performance of pavements containing materials

and/or design features that are no longer commonly used or expected to be used. Reference

pavements should be re-analyzed periodically.

Adjacent Existing Pavements – The choice of pavement type may be influenced by the

pavement types of adjacent sections that have similar conditions to the project and that have

provided adequate long-term service.

Municipal Preference, Participating Local Government Preference – While these considerations seem outside the realm of the highway engineer, the highway administrator

cannot ignore them.

Construction Considerations – Various construction considerations may influence the pavement type selection:

Seasonal construction constraints

Reduction of maintenance and protection of traffic during construction

Need for reduced future maintenance in highly congested locations

Economic impact on local businesses due to duration of construction project

Grades, Curvature and Unusual Loadings – Slow-moving vehicles starting and stopping on steep grades and unusual loadings may affect the pavement type selection.

The recommended pavement structure, chosen after careful consideration of the above

factors, will be designated on Form D-4332. Any supporting documentation for the type

selection must be included with the copies of Form D-4332 submitted to the Highway Design

and Technology Section (HDTS) of the Bureau of Project Delivery.


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11.2 LIFE-CYCLE COST ANALYSIS GUIDELINES

The policies and methodologies outlined in this Chapter define when a Life-Cycle Cost

Analysis (LCCA) must be completed and how to perform the analysis. The HDTS shall review

and update (if necessary) the policies and processes every two years, in order to keep up with and

reflect the latest innovations, technology developments and costs in the fields of pavement

design, construction, maintenance and materials. Stakeholders (including industry) should

participate in these reviews.

An LCCA must be submitted to the HDTS for all new construction, reconstruction or

major structural rehabilitation projects with at least 30,000 square yards of mainline pavement

surface work (including pavement and shoulders), regardless of roadway network or funding

system.

Structural pavement designs are performed for each pavement type alternative and the

LCCA is performed to analyze which equivalent structure is most cost-effective over a specified

analysis period. It is important that all practical alternatives are considered when performing an

LCCA for these projects, from major rehabilitation with either a bituminous or concrete

structural overlay to total reconstruction with either pavement type. Justification must be

provided when an alternate is not practical and is excluded from the LCCA.

The current LCCA Excel spreadsheet can be downloaded from:

http://www.dot.state.pa.us/Internet/Bureaus/pdBOMO.nsf/LCCA?OpenForm

The total Present Worth costs (Initial Construction + Maintenance Activities + User

Delay) of all design alternatives are to be compared and all alternates must have the same

analysis period. For treatments that extend life beyond the analysis period, apply a Residual Life

Discount to account for the value of the performance beyond the end of the analysis period:

Residual Life Discount = Present Worth Cost of Treatment x

(Age of Treatment @ End of Analysis Period/Life of Treatment - 1).

Note that “Present Worth Cost of Treatment” is the Present Worth cost of the

maintenance activity to which the Residual Life Discount is applied. It does not apply to the

User Delay Cost for that activity.

Perform the LCCA without factoring inflation. A Discount Rate shall be applied to all

costs and discounts within the analysis period. The Discount Rate is the five-year rolling

average of the annual 30-Year Real Interest Rate on Treasury Notes and Bonds posted by

Executive Office of the President, Office of Management and Budget (OMB) Circular A-94.

HDTS will provide the updated Discount Rate to all District PMEs each January, based on the

information posted at:

http://www.whitehouse.gov/omb/circulars_a094/a94_appx-c/

http://www.dot.state.pa.us/Internet/Bureaus/pdBOMO.nsf/LCCA?OpenFormhttp://www.whitehouse.gov/omb/circulars_a094/a94_appx-c/


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The cost of all bituminous items, adjusted as per Publication 408 Section 110.04, Price

Adjustment of Bituminous Materials, will be factored by the provided Asphalt Adjustment

Multiplier (AAM). The AAM is to be applied to bituminous costs for both initial construction

and future maintenance in the LCCA so as to more accurately estimate the most current unit

price of bituminous materials at the time of project bidding.

The AAM will be calculated semiannually based on the total of bituminous payments

made over the preceding twelve months and bituminous price adjustments applied to those

payments. To further clarify, the following equation will be used:

AAM = 1 + Adjustments / Total of Bituminous Payments.

The AAM will be updated and provided to all District Pavement Management Engineers

by the HDTS semiannually during the first week of each July and January.

Construction Items

The pavement items quantity estimates for each alternative will be based on the actual

typical cross section used for the project (e.g. wearing, binder, base, and subbase; or PCCP,

treated base, and subbase).

The differences in costs for pavement-related items (e.g., pavement relief joints, and

approach slabs) must be included in the LCCA when calculating initial costs. Only the

differences in these items quantities between alternatives shall be included in the LCCA; do not

include the total item quantity for each alternative.

The differences in costs for earthwork items must be included in the LCCA when

calculating initial costs. To determine the subgrade and excavation quantities, the estimated

percentage of the project in total cut, total fill, and cut and fill shall be determined for each

alternative. Only the differences in earthwork quantities between alternatives shall be included

in the LCCA; do not include the total earthwork quantity for each alternative.

Resurfacing

When calculating the total cost for resurfacing alternatives, include the cost of pavement

resurfacing, shoulder modifications, necessary pavement patching, drainage and guide rail

adjustments, maintenance and protection of traffic, etc.

For LCCA purposes, the first bituminous overlay for rigid pavements (not including

scratch or leveling courses) shall be 4" thick when 9.5 mm Wearing Course mix is used or 4.5"

thick when 12.5 mm Wearing Course mix is used. All resurfacing of flexible pavements shall be

1.5" thick when 9.5 mm Wearing Course mix is used or 2" thick when 12.5 mm Wearing Course

mix is used.

Resurfacing of flexible pavements with new and non-standard overlay materials, such as,

Thin Hot Mix Asphalt Overlays or Asphalt Rubber Gap-Graded Wearing Courses shall use the

minimum thicknesses issued in any design use guidelines for these type of new or non-standard

resurfacing materials.


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Shoulders

The LCCA must account for shoulder construction and maintenance. The shoulder type

must be structurally equivalent for each alternate, i.e., full-depth bituminous shoulders vs. full-

depth concrete shoulders.

Miscellaneous

Engineering and mobilization costs must not be included in the life-cycle cost analysis.

Regarding costs for non-pavement items, such as drainage, guiderail, utility relocations,

etc., only the differences between alternatives for these items shall be included in the LCCA. Do

not include the total item quantity in each alternative.

Type Determination

Either of the following will be sufficient to conclusively determine the pavement type:

1. A difference of 10% or more in life-cycle cost, excluding user delay costs.

2. A difference of 20% or more in life-cycle cost, including user delay costs.

3. Engineering judgment, adjacent pavement types, subgrade composition or condition,

right-of-way constraints, or other factors may provide justification for pavement type

selection, upon HDTS approval.

In all other cases, Alternate Pavement Type Bidding (Section 11.6) must be applied to

determine pavement type. The impact of constructability/phasing issues and/or maintenance and

protection of traffic constraints should be reflected by varying Initial Construction Costs, User

Delay Costs, and/or Maintenance and Protection of Traffic Costs, and not considered separately.

If an LCCA is performed more than three (3) years prior to project letting, it must be

updated to reflect current prices, traffic data, Discount Rate, Construction Cost Index and any

changes to the pavement design. For Alternate Bidding, the LCCA must be performed, or

updated, within six months of project letting. Updated LCCA documents must be submitted to

HDTS with changes indicated in red font, even if the previous LCCA has been approved by

HDTS. Documentation supporting the changes must also be submitted.

Upon approval of an LCCA and pavement type selection, pavement type shall not be

changed, whether the project is in design or construction status, unless approved by the HDTS.

11.3 GUIDELINES FOR DEVELOPING INITIAL COSTS

The following guidelines shall be used to develop initial costs for each particular

rehabilitation strategy. Adjust these guidelines to include any items that may occur on a

particular project that would affect the initial cost of a particular rehabilitation strategy.


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11.3.1 Bituminous Rehabilitation Strategies

Bituminous Overlay

1. Design according to Chapter 10.

2. Patching based on actual field measurements. The quantity shall anticipate additional

deterioration that will occur between the time of the design field view and the actual construction

of the project. Replace concrete pavement with concrete (as per Section 4.2) and bituminous

pavement with matching depths of like bituminous courses

3. Slab stabilization where necessary to restore support to the existing concrete pavement.

4. Bituminous tack coat, if necessary.

5. Continuous pavement base drain. Replace as appropriate.

6. Longitudinal and transverse joint cleaning and sealing of concrete pavements. Asphalt joint

and crack sealing on bituminous pavements. Use of heavy-duty membranes, as necessary.

Sawing and sealing of bituminous overlays on concrete or on existing sawed and sealed

bituminous."

7. Type 6 or Type 7 paved shoulders as applicable.

8. Sawing and sealing the overlay over existing transverse and patch joints.

9. Adjusting or replacing existing guide rail and drainage structures as necessary.

Bituminous Overlay on Crack and Seated Concrete

1. Cracking and seating the existing concrete pavement.

2. Base repair with Base Course/Superpave Base Course.

3. Continuous pavement base drain.

4. Leveling course (1 inch minimum), includes cross-slope correction.

5. Bituminous overlay (thickness as required by design).

6. Full-depth bituminous shoulders.

7. Resetting and/or replacing guide rail and drainage structures as necessary.

Bituminous Overlay on Rubblization

1. Rubblizing and seating the existing concrete pavement.


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2. Base repair with AASHTO #1 aggregate, as necessary.


4. Leveling course (1 inch minimum), includes cross-slope correction.

5. Bituminous thickness, as required by design.

6. Full-depth bituminous shoulders.


Bituminous Reconstruction – Remove and Replace


2. Undercutting and replacement of subgrade, if necessary.


11.3.2 Concrete Rehabilitation Strategies

Concrete Pavement Rehabilitation

1. Patching and spall repair based on actual field measurements and/or deflection tests. The

quantity shall anticipate additional deterioration that will occur between the time of the design

field view and the actual construction of the project.

2. Slab stabilization around patches and where necessary to restore full support to the pavement.

3. Slabjacking as required.

4. Diamond grinding 50% of project to improve ride quality, or to improve friction if necessary

with the exception of concrete pavements constructed with Vanport Limestone aggregate. (Data

has shown that grinding a concrete surface removes the effective mortar layer on the pavement

and the skid resistance of the exposed Vanport Limestone is susceptible to rapid decline.)


6. Rehabilitation of all failed transverse joints, if not previously performed. Otherwise, cleaning

and resealing of all joints that have the proper shape factor.

7. Cleaning and sealing all longitudinal joints and pavement/shoulder joints.

8. Adjusting or replacing guide rail and drainage structures as necessary.


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Concrete Overlays – Bonded and Unbonded

1. Design in accordance with Chapter 10.

2. Rehabilitation of all failed transverse joints.

3. Concrete pavement patching based on actual field measurements.

4. Slab stabilization around patches and where necessary to restore uniform support.

5. Cleaning and sealing all existing joints, if unbonded overlay.


7. Concrete shoulders.

8. Leveling course and bond breaker to be included, if unbonded design.

9. Adjusting or replacing all guide rail and drainage structures as necessary.

10. Fill widening to retain proper shoulder widths, and checking bridge underclearances.

Concrete Overlay - Unbonded – Crack and Seat

1. Cracking and seating existing concrete pavement.

2. Base repair with HMA Base Course/Superpave Base Course as necessary.


4. Leveling course and bond breaker includes cross-slope correction.

5. Unbonded concrete overlay, as designed using the procedure in Chapter10.




Concrete Reconstruction on Rubblization

1. Rubblizing and seating existing concrete pavement.

2. Base repair with AASHTO #1 aggregate as necessary.



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4. Leveling course and bond breaker includes cross-slope correction.

5. Concrete thickness, as required by design.




Concrete Reconstruction – Remove and Replace


2. Undercutting and replacement of subgrade, if necessary.


11.4 MAINTENANCE STRATEGIES FOR LIFE-CYCLE COST

ANALYSIS (LCCA)

11.4.1 Bituminous New Construction or Reconstruction (including construction on

rubblized concrete) – 50 Year Pavement Life

5 years Clean and Seal, 25% of longitudinal joints

Crack Seal, 500 lineal feet per mile

Seal Coat or Micro Surface shoulders, if Type 1, 1S, 3, 4, 6 or 6S

Maintenance and Protection of Traffic

User Delay

10 years Full Depth Patching, 2% of pavement area

Mill wearing course

Bituminous Inlay, 1.5" or 2.0"



User Delay



Seal Coat or Micro Surface shoulders if Type 1, 1S, 3, 4, 6 or 6S


User Delay


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Leveling Course, 60 PSY

Bituminous Overlay, 1.5" or 2.0"

Type 7 Paved Shoulders

Adjust guide rail and drainage structures, if necessary


User Delay




User Delay


Mill Wearing Course


Seal Coat or Micro Surface shoulders


User Delay




User Delay







User Delay





User Delay


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11.4.2 Concrete New Construction, Reconstruction (including construction on rubblized

concrete), Unbonded Overlay – 50 Year Pavement Life (applying Residual Life Discount)

8 years Clean and Seal, 25% of longitudinal joints including shoulders

Clean and Seal, 25% of transverse joints


User Delay

15 years Concrete Patching, 2% of pavement area

Diamond Grinding, 50% of pavement area

Clean and Seal, all longitudinal joints including shoulders

Clean and Seal, all transverse joints


User Delay





Bituminous Overlay, 4" or 4.5"

Saw and Seal, all transverse joints




User Delay

30 years Clean and Seal, 25% of longitudinal and transverse joints




User Delay

35 years Mill Wearing Course


Saw & Seal, all transverse joints



User Delay

40 years Clean & Seal, 25% of longitudinal and transverse joints




User Delay


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User Delay

Note: In Year 50, five years of life remain on the last overlay. Therefore a Residual Life

Discount is applied when comparing to New Bituminous Construction or Reconstruction in order

to equate total pavement lives.

11.4.3 Bonded Concrete Overlay – 30 Year Pavement Life



Seal Coat or Micro Surface shoulders, if bituminous


User Delay


Diamond Grinding, 50% of pavement area

Clean and Seal, 25% of longitudinal joints including shoulders

Clean & Seal, 25% of transverse joints



User Delay





User Delay





Bituminous Overlay, 4" or 4.5"

Saw and Seal, all transverse joints




User Delay


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25 years Clean and Seal, 25% of sawed and sealed joints




User Delay

11.4.4 Concrete Pavement Rehabilitation (CPR) & Bituminous Overlay – 30 Year Pavement Life

10 years Mill Wearing Course





User Delay

15 years Clean & Seal, 25% of sawed & sealed joints




User Delay








User Delay

25 years Clean & Seal, 25% of longitudinal and transverse joints




User Delay

11.4.5 Bituminous Overlay on Bituminous Pavement – 10 Year Pavement Life





User Delay


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11.4.6 Ultra-Thin Whitetopping on Bituminous Pavements – 10 Year Pavement Life





User Delay

11.5 USER DELAY COSTS

Roadway users incur User Delay Costs while roads are being maintained, repaired or

reconstructed. User Delay Costs must be accounted for in the life-cycle cost analysis for each

alternate to be compared. These costs must be determined, and included in the LCCA, for each

year of each alternate that user delays are incurred, including the year of Initial Construction if

the User Delay Costs vary for the alternates due to differences in traffic control and/or project

phasing. User Delay Costs are divided into three categories:

1. Idling Cost (or Speed Reduction Cost)

2. Time Value Costs (for Idling and Stopping)

3. Stopping Cost

If any of these types of user delays are incurred, the number of vehicles affected by the

delay must be calculated. The following sections provide an overview of the items that User

Delay Costs entail.

11.5.1 Delayed Vehicles

In order to calculate the number of delayed vehicles during an activity in a specific year,

the following traffic information is required:

1. Initial ADT, Design Year, and Design Year ADT

2. Composition of the traffic mix by vehicle class (i.e., cars, single unit trucks,

combination trucks)

3. Directional Factor

4. Total Days of the Activity

From this information, the following items must then be calculated:

Traffic Growth Factor

ADT in each Activity Year

ADT in each Direction


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ADT Delayed in each Direction

Total Number of Vehicles Delayed During the Activity

Total Number of Vehicles Delayed in each vehicle class

11.5.2 Stopped Vehicles

If during construction, the number of lanes that are being maintained is reduced, then the

capacity of the facility is affected. If the actual traffic exceeds capacity, then a backup will occur

as traffic enters the construction zone. Vehicles will be stopped due to congestion at the

restricted area, and Stopping Costs must be determined. To determine the number of vehicle

stops, the ADT for the applicable year and the composition of the traffic must be determined, as

described for determining Delayed Vehicles. In addition, the following items must be calculated:

1. Hourly breakdown of traffic

2. Roadway Capacity

The hourly breakdown (by percent of the total daily traffic) can be determined by a traffic

study. If a study is not done, Table 11.1 provides hourly percentages of total vehicles based on

average values for all roadways in a specific Traffic Pattern Group category.

Roadway Capacity is determined for one direction, and is dependent on the total number

of lanes in that direction under normal operation, and the number of lanes maintained during

construction. Figure 6-12 of the Highway Capacity Manual, Special Report 209, by the

Transportation Research Board can be used to determine roadway capacity at a desired

confidence level. For the purposes of determining the number of stopped vehicles while

calculating User Delay Costs, this figure has been simplified as shown in Table 11.2.


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Table 11.1 Hourly Percentages of Total Vehicles *

HOUR TRAFFIC PATTERN GROUP

1 2 3 4 5 6 7 8 9 10

0-1 1.23 1.80 0.83 0.81 0.73 0.80 0.77 0.72 0.80 0.81

1-2 0.90 1.49 0.51 0.54 0.42 0.52 0.47 0.43 0.47 0.50

2-3 0.82 1.38 0.42 0.48 0.34 0.47 0.40 0.35 0.39 0.34

3-4 0.85 1.39 0.45 0.56 0.35 0.52 0.47 0.37 0.42 0.34

4-5 1.13 1.58 0.76 1.00 0.64 0.94 0.90 0.70 0.77 0.59

5-6 2.23 2.29 2.04 2.47 1.84 2.23 2.48 1.96 2.13 1.45

6-7 4.81 3.62 4.74 4.76 4.46 4.30 5.05 4.37 4.68 3.01

7-8 6.58 4.69 6.71 6.10 6.46 5.76 6.32 6.09 6.34 4.79

8-9 5.86 4.83 5.97 5.61 5.80 5.50 5.45 5.61 5.62 5.01

9-10 5.14 5.12 5.12 5.28 4.99 5.38 5.08 5.12 4.96 5.14

10-11 5.11 5.46 5.09 5.39 5.00 5.54 5.17 5.26 4.97 6.47

11-12 5.29 5.67 5.42 5.59 5.45 5.85 5.42 5.60 5.28 5.99

12-13 5.45 5.72 5.72 5.80 5.86 6.07 5.80 5.93 5.62 6.30

13-14 5.52 5.89 5.75 5.99 5.75 6.18 5.73 5.98 5.64 6.39

14-15 6.04 5.27 6.32 6.57 6.34 6.82 6.45 6.56 6.31 6.83

15-16 6.97 6.78 7.34 7.54 7.53 7.82 7.66 7.74 7.60 7.86

16-17 7.46 7.05 7.84 7.91 8.11 8.00 8.11 8.12 8.10 8.51

17-18 7.20 6.50 7.68 7.42 7.93 7.26 7.61 7.69 7.83 8.12

18-19 5.52 5.31 5.93 5.59 6.16 5.58 5.74 6.04 6.16 6.31

19-20 4.35 4.40 4.58 4.32 4.89 4.41 4.47 4.81 4.85 5.23

20-21 3.71 3.92 3.80 3.63 4.07 3.68 3.78 3.97 4.04 4.20

21-22 3.29 3.49 3.16 2.99 3.20 2.88 3.05 3.10 3.22 3.12

22-23 2.59 2.94 2.26 2.14 2.21 2.08 2.17 2.11 2.28 2.20

23-24 1.95 2.41 1.56 1.47 1.45 1.41 1.45 1.37 1.52 1.48

TRAFFIC PATTERN GROUP (TPG) CATEGORIES:

1: Urban Interstate 6: North Rural Minor Arterials

2: Rural Interstate 7: Central Rural Minor Arterials

3: Urban Principal Arterial 8: North Rural Collectors

4: Rural Principal Arterial 9: Central Rural Collectors

5: Urban Minor Arterials or Collectors 10: Special Recreational

* From PennDOT, Bureau of Planning and Research, Transportation Planning Division, Pub. 601 "2007

Pennsylvania Traffic Data"Factoring Process: Traffic Adjustment Factors, Table 350.


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Table 11.2 Roadway Capacity *

Number of Lanes (1 direction)

Capacity

(veh/hr/lane)

Normal

Operation

During

Construction

3 1 1000

2 1 1260

5 2 1340

4 2 1430

3 2 1440

4 3 1480

* From Figure 6-12 of the Highway Capacity Manual, Special Report 209, by the

Transportation Research Board, based on ninety percent confidence level.

11.5.3 Example Calculations

EXAMPLE 1

Urban Interstate

Initial ADT (Year 2010) = 30,500 Traffic Breakdown (by vehicle type):

Design Year ADT (Year 2030) = 49,978 88% Cars

Directional Distribution Factor = 0.50 12% Trucks - 20% Single Unit

- 80 % Combination

Traffic Breakdown (by percentage):

HOUR %

VEHICLES HOUR %

VEHICLES HOUR %

VEHICLES

0-1 1.23 8-9 5.86 16-17 7.46

1-2 0.90 9-10 5.14 17-18 7.20

2-3 0.82 10-11 5.11 18-19 5.52

3-4 0.85 11-12 5.29 19-20 4.35

4-5 1.13 12-13 5.45 20-21 3.71

5-6 2.23 13-14 5.52 21-22 3.29

6-7 4.81 14-15 6.04 22-23 2.59

7-8 6.58 15-16 6.97 23-24 1.95

Under normal conditions, the roadway has two lanes in each direction. Calculate the

number of delayed and stopped vehicles in each class during the maintenance activities in Year

15 (2025) if one lane will be maintained in one direction as follows:

1) Traffic Growth Factor = (49,978 / 30,500)[1/20] = 1.025

2) Percent of Daily Vehicles Delayed = 100 (Lanes will remain closed all day, and traffic in both directions is affected)

3) ADT in Year 2025 = 30,500 x 1.0 x (1.025)[15] = 44,173


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4) ADT in One Direction = 44,173 x 0.50 = 22,087

(Since the Directional Distribution Factor equals 0.50, the ADT is the same in both

directions.)

5) ADT in One Direction for each Hour:

HOUR VEHICLES HOUR VEHICLES HOUR VEHICLES

0-1 272 8-9 1,294 16-17 1,648

1-2 199 9-10 1,135 17-18 1,590

2-3 181 10-11 1,129 18-19 1,219

3-4 188 11-12 1,168 19-20 961

4-5 250 12-13 1,204 20-21 819

5-6 493 13-14 1,219 21-22 727

6-7 1,062 14-15 1,334 22-23 572

7-8 1,453 15-16 1,539 23-24 431

6) Roadway Capacity in One Direction = 1260 veh/hr

(From Table 11.2, one lane open in each direction)

(Note that the hour from 7:00 am to 8:00 am is the first hour of the day that capacity

is exceeded.)

7) Number of Vehicle Stops in One Direction:

Number of Hourly Vehicle Stops in One Direction =

(Hourly % of Vehicles) x (ADT in One Direction) -

(Roadway Capacity in One Direction) + (Previous Hour's Queue)

Since the Directional Distribution Factor and the lane configuration is the same in both

directions, the Roadway Capacity and the Number of Hourly Vehicle Stops in both directions is

the same.


0-1 0 8-9 227 16-17 741

1-2 0 9-10 102 17-18 1,071

2-3 0 10-11 0 18-19 1,030

3-4 0 11-12 0 19-20 731

4-5 0 12-13 0 20-21 290

5-6 0 13-14 0 21-22 0

6-7 0 14-15 74 22-23 0

7-8 193 15-16 353 23-24 0

Total = 4,812 vehicles/day

8) Total Number of Stopped Vehicles = 4,812 x 2 = 9,624 vehicles/day

(Conditions are the same in both directions)

9) Total Number of Vehicles Delayed During Activity = 22,087 x 2 = 44,174

vehicles/day in both directions


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10) Total Number of Vehicle Stops During Activity = 4,812 x 2 = 9,624 vehicles/day in

both directions

11) Vehicles Delayed by Class:

Cars: 44,174 x 0.88 = 38,873

S.U. Trucks: 44,174 x 0.12 x 0.20 = 1,060

Comb. Trucks: 44,174 x 0.12 x 0.80 = 4,241

12) Vehicle Stops by Class:

Cars: 9,624 x 0.88 = 8,469

S.U. Trucks: 9,624 x 0.12 x 0.20 = 231

Comb. Trucks: 9,624 x 0.12 x 0.80 = 924

EXAMPLE 2

All of the same conditions as Example 1, except one lane in each direction will be

closed only during the hours of 8:00 am to 4:00 pm (8 hours):

1) Percent of Daily Vehicles Delayed = 45.7

(Sum of the Hourly Percentages of Total Traffic for the hours of lane closure.)

2) ADT Delayed in One Direction = 22,087 x 0.457 = 10,094

(Since the Distribution Factor equals 0.50, the ADT is the same in both directions.)

3) Number of Hourly Vehicle Stops in One Direction:


0-1 0 8-9 34 16-17 0

1-2 0 9-10 0 17-18 0

2-3 0 10-11 0 18-19 0

3-4 0 11-12 0 19-20 0

4-5 0 12-13 0 20-21 0

5-6 0 13-14 0 21-22 0

6-7 0 14-15 74 22-23 0

7-8 0 15-16 353 23-24 0

Total = 461 vehicles

8) Total Number of Stopped Vehicles = 461 x 2 = 922vehicles

(Conditions are the same in both directions)

9) Total Number of Vehicles Delayed During Activity = 10,094 x 2 = 20,188

vehicles/day in both directions

10) Total Number of Vehicle Stops During Activity = 461 x 2 = 922 vehicles/day in

both directions


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11) Vehicles Delayed by Class:

Cars: 20,188 x 0.88 = 17,765

S.U. Trucks: 20,188 x 0.12 x 0.20 = 485

Comb. Trucks: 20,188 x 0.12 x 0.80 = 1,938

12) Vehicle Stops by Class:

Cars: 922 x 0.88 = 811

S.U. Trucks: 922 x 0.12 x 0.20 = 22

Comb. Trucks: 922 x 0.12 x 0.80 = 89

11.5.4 Added Time

Due to the reduced speeds, travel time is increased for all vehicles that pass through a

construction zone. This added time must be determined in order to calculate User Delay Costs.

The added time may be dependent on the traffic control pattern to be implemented (i.e., high-

speed crossovers, detours, etc.).

For each traffic control pattern to be implemented during the life-cycle, the following

information must be known:

1. Restricted Flow Length

2. Initial and Reduced Speeds

The following items must then be calculated:

1. Restricted Flow Time

2. Overall Increased Travel Time

The Restricted Flow Length is the length of roadway for which a speed reduction or lane

closure is implemented. If traffic is detoured, the detour length is the Restricted Flow Length.

The Restricted Flow Time is the time required to travel through the Restricted Flow

Length. If traffic is detoured, then the Restricted Flow Time equals the time necessary to travel

through the Detour Length. Restricted Flow Time is used to determine Idling Costs.

The Overall Increased Travel Time is the difference between the Restricted Flow Time

and the time required to travel the same distance at the normal posted speed limit. Overall

Increased Travel Time is necessary to compute the Time Value Cost for Idling.

For each traffic control pattern that applies a different Restricted Flow Length, Initial

Speed, or Reduced Speed, there is a different Restricted Flow Time and the Overall Increased

Travel Time.


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11.5.5 Cost Factors

Cost factors for Stopping, Idling, and Time Value were determined for cars, single-unit

trucks, and combination trucks in 1972 and were published in NCHRP Report 133, Procedures

for Estimating Highway User Costs, Air Pollution, and Noise Effects. (Table 11.3 presents the

information from Table 5 of NCHRP Report 133.) The Time Value Costs were $3.00/hr for

cars and $5.00/hr for all trucks.

11.5.6 Inflation Factor

The cost factors shown in Table 11.3 are inflated to present day costs by use of the

Inflation Factor, which is based on the Engineering News-Record (ENR) Construction Cost

Index. The 1972 Construction Cost Index is 1753. The current Construction Cost Index is

found in the current edition of ENR under "Market Trends."

The Inflation Factor (I) is determined as follows:

I = Current Index

1972 Index

Table 11.3 Added Time and Vehicle Running Costs Per 1000 Stops,

and Idling Costs (Shading indicates interpolated values)

Initial

Speed

(mi/hr)

Added Time (hr/1000 stops)

(excludes Idling Time)

Added Cost ($/1000 stops)a

(excludes Idling Cost)

Passenger Car Single Unit

Truck

Combination

Truck

Passenger Car Single Unit

Truck

Combination

Truck

5 1.02 0.73 1.10 0.71 2.43 8.83

10 1.51 1.47 2.27 2.32 5.44 20.35

15 2.00 2.20 3.48 3.98 8.90 34.13

20 2.49 2.93 4.76 5.71 12.71 49.91

25 2.98 3.67 6.10 7.53 16.80 67.37

30 3.46 4.40 7.56 9.48 21.07 86.19

35 3.94 5.13 9.19 11.57 25.44 106.05

40 4.42 5.87 11.09 13.84 29.83 126.63

45 4.90 6.60 13.39 16.30 34.16 147.62

50 5.37 7.33 16.37 18.99 38.33 168.70

55 5.84 8.07 20.72 21.92 42.25 189.54

60 6.31 8.80 27.94 25.13 47.00 209.82

65 6.78 9.53 37.65 28.63 51.43 227.69

70 7.25 10.16 49.54 32.46 55.67 247.21

75 7.71 10.89 64.41 36.64 59.84 266.72

80 8.17 11.60 82.74 41.19 64.39 288.84

Idling Cost ($/veh-hr)b 0.1819 0.2017 0.2166

a Includes fuel, tires, engine oil, maintenance, and depreciation.

b Includes fuel, engine oil, maintenance, and depreciation.

Source: R. Winfrey, Economic Analysis for Highways (International Textbook Co.,

1969) 923 pp.


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11.5.7 Example Calculations (continued)

Calculate the User Delay Costs based on the total number of delayed and stopped

vehicles that were calculated in Section 11.5.3, Example 1:

Delayed: Stopped:

Cars: 38,873 Cars: 9,624

S.U. Trucks: 1,060 S.U. Trucks: 231

Comb. Trucks: 4,241 Comb. Trucks: 924

The following information is also known:

Restricted Flow Length = 4.7 miles

Initial Speed = 55 mph

Reduced Speed = 40 mph

Current Construction Cost Index = 8,574

1) Restricted Flow Time = Restricted Flow Length/Reduced Speed = 4.7/40 = 0.1175

hr

2) Overall Increased Travel Time =

(Restricted Flow Length / Reduced Speed) - (Restricted Flow Length / Initial Speed)

= (4.7/40) - (4.7/55) = 0.0320 hr

3) Inflation Factor = Current Index / 1972 Index = 8,574/1753 = 4.891

4) Cost Factors (From Table 11.3):

Added Time Added Cost Idling Time Time Value

(hr/1000 stops) ($/1000 stops) ($/veh-hr) ($/hr)

Cars 5.84 21.92 0.1819 3.00

S.U. Trucks 8.07 42.25 0.2017 5.00

Comb. Trucks 20.72 189.54 0.2166 5.00

5) Current Cost Factors:

Added Time Added Cost Idling Time Time Value

(hr/1000 stops) ($/1000 stops) ($/veh-hr) ($/hr)

Cars 5.84 73.40 0.6091 10.05

S.U. Trucks 8.07 141.48 0.6754 16.74

Comb. Trucks 20.72 634.68 0.7253 16.74


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6) User Delay Costs:

Number

of Added Delay Cost

Vehicles Time per Unit COST

CARS

Idling 38,873 x 0.1175 x 0.6091 = 2,782

Time Value/Idling 38,873 x 0.0320 x 10.05 = 12,502

Stopping 9,624 x 0.001 x 73.40 = 706

Time Value/Stopping 9,624 x 5.84/1000 x 10.05 = 565

S.U. TRUCKS

Idling 1,060 x 0.1175 x 0.6754 = 84

Time Value/Idling 1,060 x 0.0320 x 16.74 = 568

Stopping 231 x 0.001 x 141.48 = 33

Time Value/Stopping 231 x 8.07/1000 x 16.74 = 31

COMBINATION TRUCKS

Idling 4,241 x 0.1175 x 0.7253 = 361

Time Value/Idling 4,241 x 0.0320 x 16.74 = 2,272

Stopping 924 x 0.001 x 634.68 = 586

Time Value/Stopping 924 x 20.72/1000 x 16.74 = 320

TOTAL $ 20,810

11.5.8 Days of Construction

The total daily User Delay Cost is multiplied by the total number of Days of

Construction that the roadway will be under repair. The total number of Days of Construction

is determined by applying daily production rates to the specific work activities to be performed,

accounting for concurrent activities, and summing the days of controlling operations.

Production rates will vary depending on whether the Maintenance and Protection of Traffic is a

short-term (partial-day) or long-term (full-day) closure. Standard values to be used in LCCAs

are provided in Table 11.4; these values are based on typical production rates provided by

industry.

Concurrent activities are indicated and accounted for in the LCCA Excel spreadsheet, so

that the total days for each maintenance year reflect the total required time of closure and not the

sum of each activity’s duration in that year.


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Table 11.4 Standard Production Rates for Maintenance Activities

Production Rate Per Shift

Activity

Short Term

Closure

Long Term

Closure

Adjust Drainage Structures 8 inlets 10 inlets

Bituminous Inlay or Overlay 1,800 tons 2,400 tons

Clean & Seal Transverse Joints – concrete surface 3,200 LF 4,200 LF

Clean & Seal Joints – bituminous surface 6,000 LF 8,000 LF

Clean & Seal Longitudinal Joints – concrete surface 6,500 LF 8,500 LF

Concrete Patching 300 SY 400 SY

Crack Seal 6,000 LF 8,000 LF

Diamond Grinding 1,500 SY 2,000 SY

Full-Depth (Bituminous) Patching 75 CY 150 CY

Leveling Course, 60 PSY 1,800 tons 2,400 tons

Mill Wearing Course 16,400 SY 21,900 SY

Reinstall Guide Rail 1,500 LF 2,000 LF

Remove Existing Guide Rail 2,250 LF 3,000 LF

Saw & Seal Transverse Joints 6,400 LF 8,500 LF

Seal Coat or Micro Surface Shoulders 16,000 SY 18,000 SY

Type 7 Paved Shoulders 1,800 tons 2,400 tons

11.6 ALTERNATE BIDDING

The following guidelines on Alternate Bidding have been developed to facilitate

competition in the paving industry, and to allow PennDOT to realize bid savings for construction

projects and take advantage of fluctuating material costs without compromising sound

engineering principles and practices.

It is in the best interest of PennDOT to apply Alternate Bidding whenever appropriate so

that both industries are competitive and lower costs can be realized. Rather than a predetermined

pavement type selection based on an LCCA and historical cost information, there is motivation

to determine pavement type based on low bid. Both industries will be made aware of the

upcoming Alternate Bidding project through a formal quarterly direct mailing by the HDTS.

Alternate Bidding requires the determination of a C-Factor which accounts for future

maintenance costs, but excludes User Delay Costs, and is added to the construction cost so that

the low bid is based on life-cycle costs. Additional requirements for Alternate Bidding are as

follows:

Alternates must be “equivalent,” meaning they provide comparable levels of service and performance over the same analysis period.

The bid package will indicate the appropriate C-Factors for each alternative, determined by PennDOT based on LCCA methodology for the project.


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Typical sections for all alternatives must meet RC standards, DM-2 and Pub. 242 requirements.

Lane width, shoulder width, cross slope and all other geometric features unrelated to pavement type, shown on the Typical Sections must remain as per the plans.

11.6.1 Alternate Bidding Project Selection

Alternate Bidding shall be considered for any new construction, reconstruction or major

structural rehabilitation project. Alternate bidding stimulates competition in the paving market,

resulting in the potential for considerable savings in construction costs. Enhanced competition in

the paving market also spurs innovation and improved pavement quality. Alternate bidding also

takes advantage of fluctuating material costs that cannot be predicted during the preconstruction

phase of a project.

When an LCCA is not required for a project, as per Section 11.2, pavement type selection

is based on initial costs or other factors. Alternate Bidding may still be considered in these

cases, with no C-Factor calculation, using alternate designs that have the same scope of

treatment, service lives and expected performance, and with approval by the HDTS.

When a new construction, reconstruction or major rehabilitation project requires an

LCCA, Alternate Bidding must be applied, except as defined in Section 11.2, “Type

Determination,” or with approval by the HDTS. The HDTS is responsible for monitoring and

tracking Alternate Bidding projects and results.

For Alternate Bidding projects, pavement type shall not be changed after the project is

awarded to a contractor unless approved by the HDTS. The pavement type selection was the

basis of the contract award and post-award change orders for pavement type negate the purpose

of the alternate bidding process.

Alternate Bidding projects may be advertised in one of three ways:

1. Plans, cross-sections, typical sections, quantities, and traffic control plans are not

developed prior to bid for any alternate.

2. Plans, cross-sections, typical sections, quantities, and traffic control plans are

developed for one pavement alternate prior to bid. Typical sections are provided for all

alternates.

3. Plans, cross-sections, typical sections, quantities, and traffic control plans are

developed for all pavement alternates prior to bid.

For options 1 and 2, any alternate that is not designed prior to bid must be accompanied

with Design-Build provisions.

For options 2 or 3, bidders may also propose an alternate design with the same pavement

type as the “as designed” pavement structure; all applicable revisions to plans, cross-sections,

typical sections, quantities, traffic control plans must be developed by the bidder.


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Options 1 and 3 are preferred methods for advertising Alternate Bidding projects because

they allow all bidders to develop bids from comparable amounts of information and provide no

bidders with an inherent advantage in preparing cost estimates and bid documents. Option 2

should only be considered for projects in the Final Design phase prior to April 1, 2013 and

development of a full set of complimentary plans will result in a significant delay in advertising a

project. Although option 3 may increase the burden on the Department during the

preconstruction phase (design and management), the benefits of competition potentially

outweigh the burden.

11.6.2 C-Factor Calculation

The C-Factor is determined by summing the Present Worth (PW) value of the future

Maintenance and the Residual Life Discount determined by the LCCA:

C = (PWmaint + Residual Life Discount)

Where:

C = C-Factor

PWmaint = PW of future maintenance costs, excluding User Delay Costs

Residual Life Discount = Treatment Present Worth Cost x (Age of Treatment @ End of Analysis

Period/Life of Treatment - 1).

CHAPTER 11 PAVEMENT TYPE DETERMINATION 11.1 PAVEMENT … · 2013. 4. 3. · Publication 242,...

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