1. TxDOT ACEC Joint Educational Program (Dallas/Ft. Worth) Winter 2018
Contract Time Determination
TxDOT ACEC Joint Educational Program (Dallas/Ft. Worth)
Winter 2018
Mike

2. Mike

3. Contract Time FHWA Definition
“Contract time is the maximum time allowed in the contract for completion of all work contained in the contract documents”
Nabeel

4. FHWA Requirements for Contract time and contract time extensions
§ 23 CFR Contract time and contract time extensions
Date:
(a) The State transportation department should have adequate written procedures for the determination of contract time
These procedures should be submitted for approval to the Division Administrator within 6 months of the effective date of this Final Rule
(b) Contract time extensions granted by a State transportation department shall be subject to the concurrence of the Division Administrator and will be considered in determining the amount of Federal participation. Contract time extensions submitted for approval to the Division Administrator, shall be fully justified and adequately documented
Nabeel

5. 2014 TxDOT Standard Specifications
8.3 COMPUTATION OF CONTRACT TIME FOR COMPLETION
The number of working days is established by the Contract. For Contracts with work orders, the number of working days is established in each work order. Working day charges will begin when work begins as prescribed in Article 8.1., “Prosecution of Work.” Working day charges will continue in accordance with the Contract.
Upon request, the Engineer will provide the conceptual time determination schedule to the Contractor for informational purposes only. The schedule assumes generic resources, production rates, sequences of construction and average weather conditions based on historic data. The Department will not adjust the number of working days and milestones, if any, due to differences in opinion regarding any assumptions made in the preparation of the schedule or for errors, omissions, or discrepancies found in the Department’s conceptual time determination schedule.
Nabeel

6. FHWA Contract Time Determination (CTD) Guidelines
Based on a full evaluation of all factors involved
Typical contractor organization likely to bid on the work
Local field and weather conditions
Complexity of the work
Sequence of construction
Method of traffic handling
Additional factor in CTD
Completion Urgency
Nabeel

7. Additional Reasons for Good CTD
“Too short”
Impacts on bid prices from inefficiency to schedule resources, procure materials, etc.
“Too long”
Inconvenience to the traveling public from construction activities taking too long
Nabeel

8. Essential Elements of a CTD Schedule
Scope of work
Identify the scope of work for scheduling needs
Develop a WBS and/or Activities
Establish production rates
Standard rates of production for activities
Adaption of rates for specific projects
Establishing constraints
Procurement / fabrication of long lead items
Needs of the adjacent businesses / communities that will impact the work
Restrictions on nighttime work
High profile events
Nabeel

9. Elements of a CTD Schedule (cont.)
Impacts of the lane-closure restrictions on scheduling and logic
Seasonal limitations
Weather, temperature, daylight hours, etc.
Letting month, start of the construction activities
Affects from adjacent projects
Third party construction projects, i.e., city projects
NOTE: This presentation focuses on traditional Design-Bid-Build
Nabeel

10. Production Rates
Scott

11. Production Rates Project Manager supplies project quantities
Apply standard production rates and adjustments to establish a construction duration
The production rate should include time for the specific work item and all related activities
Example:
Placing concrete for bridge decks:
Account for mobilizing equipment, placing forms, placing steel, tying steel, inspection of steel and forms, placing concrete, as well as cure time for the deck
Scott
A production rate is the quantity produced or constructed over a specified time period.
Estimating realistic production rates is important when determining appropriate contract completion time.
The quantities should taken from the plans for the major work items by phase.
The production rate should include time for associated activities
For example; when estimating the production rate for bridge decks, make sure to account for formwork, reinforcing, inspection, placing concrete, and concrete cure time

12. Production Rates Production rates can vary due to many variables
Location
Weather
Labor conditions
Site conditions
Traffic
Availability of Resources (i.e., natural disasters)
Production rates are not a one size fits all solution
Scott
Selecting an appropriate production rate for any given work item is dependent on several variables:
The location of the project can affect the availability of resources as well as the work zone area and times available to work
Rural, Small City, and large metroplexes
Weather can obviously play a major factor in work production. Temperature, rain, wind, and snow certainly affects production
Labor conditions affect the availability of the work force
Site conditions differ greatly from project to project
Would you use the same production rate for constructing drill shafts on a level terrain vs in bottom wetlands?
Traffic conditions, such as inside median widening on a busy highway vs shoulder widening on a rural 2-lane FM road, are also major factors
The current state of the economy, such as the recent hurricanes, affect availability
Production rates will vary from project to project

13. 1992 Texas A&M Transportation Institute Research Project
Study completed in November 1992
Developed the Contract Time Determination System (CTDS)
5 most common factors that impact Construction production rates
Location (L)
Traffic conditions (T)
Complexity (C)
Soil Conditions (S)
Quantity of work (Q)
Scott
In 1992, Texas A&M TTI developed the Contract Time Determination System (CTDS).
The primary objective was to develop a rational procedure for TxDOT to determine the time required to complete a construction contract for different types of highway construction projects.
The CTDS is a conceptual estimating system for predicting contract time for highways.
This should not be used for the detailed planning of actual construction activities for a project.
This study has been the basis for TxDOT’s contract time.
Although this study is a little dated, the results and methods are still valid.
Experienced project managers can use this to develop a reasonable time determination.
The study applied the 5 most common factors that impact Construction production rates:
Location (L)
Traffic Conditions (T)
Complexity (C)
Soil Conditions (S)
Quantity of Work (Q)

14. CTDS Production Rates Scott
For major work categories, this table lists the appropriate unit of measure and the estimated daily production rate.
The daily production rates are broken down by Low, Average, and High.
For any given work item, lower production rates equates to longer durations whereas higher production rates results in shorter durations.
The production rate used (low, average, or high) does not need to be consistent for all work items.
Remove Old pavement can use the ‘Low’ value whereas Box Culverts can use the ‘High’ value.
Experienced construction managers can assist with determining the appropriate production rates

15. CTDS Production Rates Scott
In addition to the ‘standard’ rates, the five most common factors that impact highway construction projects were given ‘sensitivity’ values to be applied to selected work item.
The 5 sensitivity factors are:
Location (L)
Traffic Conditions (T)
Complexity (C)
Soil Conditions (S)
Quantity of Work (Q)
These factors are not all applied to each work item, each work item was evaluated to determine which factors most applied.
These are listed in CAPITAL LETTERS.
For example, ‘Remove Old Pavement’ only uses the Location sensitivity factor (L) and ‘Lime Stabilization’ uses two factors Soil Condition (S) and Quantity of Work (Q).

16. CTDS Job Correction Factors
Scott
It is recommend to use only 2 sensitivity factors for any given work item.
The Sensitivity factors are listed on the table shown.
Highly recommended to use only 2 Sensitivity Factors for each work item

17. CTDS Job Correction Factors
Example:
Embankment-base 4200 cy/day
Sensitivity:
Soil Condition (S) = fair = 0.85
Quantity of Work (W) = medium = 0.88
Adjusted Production Rate =
4200 x 0.85 x 0.88 = 3142 cy/day
Scott
It really sounds more complicated than it is. Let’s go through an example.
For this project, we want to develop the daily production rate for ‘Embankment’
We determine the base production rate of 4200cy/day. Going back to Table 3.3, we see that the low value was 1200cy/day, the average value is 3500cy/day, and the high value is 7000cy/day. So this value is slightly above average.
Using Table 3.4, we see that the sensitivity factors should include Soil Condition (S) and Quantity of Work (Q). From a project assessment, the soil conditions are consider ‘Fair’ at 0.85 and the quantity is considered ‘Medium’ at 0.88
Using simple multiplication, the selected Daily Production Rate comes out to 3142cy/day. Comparing this back to Table 3.3, we see that the factors have reduced the rate from above average to slightly below average.
There is a lot of subjectivity in determining the appropriate Production rate. This is where experience really helps.
I’ll now turn it over to Ryan, who will discuss other methods

18. HYPRIS Includes production rate data on 26 work items
Includes data from TxDOT projects from March 2002 through June 2004
Allows for some adjustments depending on the type of item being considered
Provides a range of production rates in table form
Ryan

19. HYPRIS
Ryan

20. HYPRIS
Ryan

21. Activities
Travis

22. Agreement with TCP
It is important to consider your TCP when developing your activities
The activities should be broken up by phase to match your TCP
All major work items on the critical path should be included
Travis

23. Concurrent Activities
Consider whether or not activities can be completed concurrently.
It’s important to identify the critical path and what items are independent of the critical path.
Note in the example below the base preparations and the traffic items that are completed concurrently with the completion of the bridge.
Travis

24. Concurrent Activities
Notice the critical path in the example below: ABUT CONCRETE -> HANG BEAMS -> REINF CONC SLAB -> BRIDGE RAIL
The beams cannot be hung until the abutment concrete is complete, BUT the Stone Riprap can begin and be completed independently of the critical path items. Same with the flex base, end treatments and seeding.
Travis

25. Activity Selection
Do not need to include every single item in the Contract Time Determination.
At a minimum, the Contract Time Determination should include:
Any Major Items
Critical Path Items (i.e., can’t place the bridge deck until the beams are hung)
Items with “mellowing” periods (i.e., lime-treated subgrade or flex-base)
Unique items to the project
Long lead time items (i.e., steel fabrication)
An example of grouping items together would be:
SW3P items (i.e., Rock filter dam, silt fence and construction exits)
Installing Signs
Installing Pavement Marking
Travis

26. Activity Selection Notice the level of detail
Keep it simple, but follow the Traffic Control Plan
This is NOT a Contractor’s Construction Schedule
For joint-bid projects (i.e. utilities), include those work items in Contract Time Determination
Travis

27. Activity Duration
The activity duration is simply the expected quantity of the item multiplied by the estimated production rate.
Example: Bridge Deck
Quantity = 2,700 CY
Production Rate = 150 CY/DAY
Activity Duration = 2,700 / 150 = 18 DAYS
Travis

28. Contract Time Determination Workshop
Travis

29. Contract Time Determination Workshop
Typically held during or after the 95% (90%) PS&E submittal.
The TxDOT Project Manager organizes this meeting and invites the following people:
Consultant Project Manager and appropriate staff
TxDOT Project Manager and appropriate staff
TxDOT Area Engineer and appropriate staff
The purpose of the meeting is to go through the Contract Time Determination with the Area Office staff and review activities, durations and predecessor/successor relationships
The TxDOT PM should bring the following:
PS&E plans of each of the TCP phases (a roll works best with the aerial turned on)
PS&E TCP Narrative and Typical Sections
PS&E Summary Sheets
Contract Time Determination
Backup for production rates
Currently being done in the Dallas District, being considered in Fort Worth
Travis

30. District Specific Calculations
Travis

31. Working Days Workweek 5 – Day Workweek 6 – Day Workweek
Seven – Day Workweek
Standard Workweek
Travis – depending on the number of days in a week, coordinate with TxDOT PM and will be made at the administration level at TxDOT. Historically, TxDOT does not prefer a 6 day work week; TxDOT may calculate the number of days it would take in a 6 day week and then give 5 day weeks; contractor can work on the Saturday to catch up. Give them more time without penalizing them.
Calc the months on 5 day week IE 12 mos
Back calc the number of days required for 6 day week to get to 12 months

32. Dallas District Contract Time
The following calculations will determine the contract time and barricades based on the activity relationships, production rates and quantities.
Historical Trend for Dallas District
2.92 rain days per month
3.42 days too wet
0.36 other
TOTAL: 6.7 Non Working Days Per Month
6.7/30.4 = 0.22
USE 1.22 as factor to account for non working days
Travis
.22 is the number of days your going to lose, in order to increase, we increase the number of days by that percentage.

33. Dallas District Contract Time
Travis

34. Fort Worth District Contract Time
Quantities are broken down for contract time determination; quantities should be submitted to project manager for reference.
Use 5 day work week, typically - verify with area office
Emphasize importance of accurate phase quantities; model the time accurately
Accuracy of quantities of major work items in phasing
Curing time is accounted for in the production rates; engineer should evaluate the results

35. Fort Worth General Notes
W = computed work time (contractor operations, production rates and sequencing)                 
A = Available work days per month (16 if project duration < 12 months; 
18 if 12 months < project duration < 24 months;             
 19 if project duration > 24 months             
B = Barricade and Traffic Handling Time (Pay Item 502)           
C = Contract Time (days)                  
 B = W/A (round up to nearest whole month)             
 C = B x (256/12)

36. Fort Worth Example

37. Additional Resources
Mike

38. Additional Resources HYPRIS
TTI Contract Time Determination System (CTDS)
FHWA Technical Advisory – Contract Time Determination
TxDOT ONLY – Internal Link - Timeline
ACEC Dallas Website
Mike