Alternate Bid Pavement Type Selection OR

Transcription

1 Alternate Bid Pavement Type Selection OR Whose coin should we flip? Curt Turgeon PE Mn/DOT Pavement Engineer February 12, 2009 Pavement Conference

2 Topics for Today MN Current Pavement Selection General Information on Alternate Bids for Pavement Selection Specific Experiences with Alternate Bids What is planned in Minnesota

3 MN Pavement Selection Reader s s Digest Version New or Reconstructed Pavements 2-3 years prior to letting District requests a selection and provides soil and traffic Standard pavement typical sections are developed Central Office does Zero-Based cost estimates for constructing each typical Maintenance costs for 50-years are determined and brought to today s s cost using a discount rate The lowest combination of constructing and maintaining is the winner* Without changing pavement type, District may elect to build an enhanced pavement typical *Appeal process is available for special considerations

4 Mn Pavement Selection Cont. Last updated September 2004 Six projects gone through system since No Projects for nearly two years

5 Mn Pavement Selection Cont. Results of the six new process Projects Calculated Difference between the low cost and next to low cost alternative type 7.9%, 6.8%, 5.2%, 4.7%, 2.1%, 1.3%

6 Mn Pavement Selection Cont. Re-analyzed 13 previous projects using the new system Calculated Difference between the low cost and next to low cost alternative type 4 projects > 20% difference 0 projects < 20% but > 10% difference 6 projects < 10% but > 5% difference 3 projects < 5% difference

7 Alternate Bid Considerations PROS Real Prices Actual Cross Sections Done at time of Bid More Bidders Competition leads to lower prices LCCA difference included at time of bid CONS Comparable Typical Sections (enhancements influence outcomes) Incentive Specifications Pay Items Producing Two Plans? Staging Differences

8 Other Issues Raised Must be ready to accept outcome Other issues aren t t addressed, project time, need for detours Typically there is always HMA on both projects Someone will buy the project Pavement isn t t the deciding factor in bid

9 New LCCA Policy Informal Requirement for Years All pavement projects must have an LCCA Done as part of the District Materials Design Recommendation 30 year analysis period Must compare AC and PCC fixes District not mandated to build lowest LCCA

10 Other States Use of Alternate Bid Implemented Ontario Louisiana Missouri No Longer Use Alabama Ohio Michigan Experimenting Utah Maryland Tennessee North Dakota Minnesota FHWA Discourages alternate bids to determine mainline pavement type. Source: Tim Aschenbrenner, Colorado DOT - AASHTO SURVEY

11 Experience from Ontario Six Projects Between All went to PCC Lowest PCC vs. Lowest HMA total from all projects was $28.5 million (C) Future enhancements Congestion, user delays Accidents Fuel savings and greenhouse gas issues Noise

12 Experience from Louisiana Old Policy: Urban= PCC, Rural = HMA Current Policy: Do LCCA If LCCA reveals difference > 25%, use low cost If LCCA reveals difference < 25%, use alternate bids

13 Experience from Louisiana Total of 37 Projects Pre-Katrina 69% went HMA ($35/ton) Post-Katrina 50% gone HMA ($80/ton) Post Katrina Alternate Bid Projects 3.4 bidders 10% under Engineer s Est All Other Projects 2.4 bidders 14% over Engineer s Est

14 Experience from Missouri Use MEPDG software to determine typical sections Standard procedure First cost has been overriding factor on 78 of the first 80 projects let. Increased the average number of bidders/project from four to five Decrease in unit costs on Alt. Bid projects PAY ITEM is Square Yard: Bit or Concrete difference in thickness is made up with base and is included in the unit price

15 Minnesota Portion of TH 212 Design Build let Alternate Bid Two Projects set for letting Other Projects in development Will use Pavement Selection Policy except will use bid prices instead of CO Estimating for construction costs Maintenance Cost factor will be included in calculation to select low cost pavement Provide staging for more complicated type

16 Minnesota Things to Reconcile Design Time and Details, automated grading, standards call for different pavement widths. Incentive Specifications HMA = Ride, Density PCC = Ride, Air Content, Dense Agg Gradation (Opt), Aggregate Quality (Opt) Pay Items did not streamline for current years projects Base Typical Section and Enhancements

17 SP TH 23 TH 23 from TH 19 to Lyon CSAH 33 Letting 2/27/ miles Convert inplace 2-lane into four lanes

18 Typical Section Information PCC DESIGN 8.5 thick PCC 4 thick OGAB 3 thick Class Select Grading AC DESIGN Wear (SP WEB440C) 4 Wear (SP WEB440C) 3 Non Wear (SPNWB430B) 11 Class 5 12 Class 3 24 Select Grading 54 of STUFF either product

19 SP TH 23 TH 23 from Lyon CSAH 33 to Cottonwood Anticipated Letting 2/27/ miles Alternate Bid on Shoulders Only Mainline will be mill and PCC inlay

20 OTHER PROJECTS 2009, TH 53 Southbound, near Twig will provide Pavement Type alternatives. (potential stimulus project) 2009, Nine Counties will let projects this year. Wabasha, Faribault, Fillmore, Meeker, Rice, Rock, Watonwan, Winona and Wright. TH 60 from Bigelow to Worthington will use alternate bid. TH 53 from TH 1 to Cook ( Letting 9/2011)

21 Beyond New Construction Asphalt vs. Concrete Missouri DOT Examples Ultra Thin Bonded Wear Course vs. Thin Overlay Hot Inplace Recycle with UTBW vs. Medium Overlay Cold Inplace Recycle or Reclamation and Medium Overlay vs. Thick Overlay Thick AC Overlay vs. 5 5 Thick Unbonded Concrete Overlay

22 WITH EXPERIENCE COMES PATIENCE Questions