pected margin of change within the meaning of the clauses "Changes" and "Differing Site Conditions" in the "General Provisions" of the contract as not requiring or permitting any adjustment of contract prices:

(a) When the quantity of work to be done or material to be furnished under any major item of the contract is increased to more than 125 percent of the quantity stated in the bid schedule then either party to the contract, upon demand, shall be entitled to an equitable price adjustment on that portion of the work above 125 percent of the quanity stated in the bid schedule.

(b) When the quantity of work to be done or material to be furnished under any major item of the contract is reduced to less than 75 percent of the quantity stated in the bid schedule then either party to the contract, upon demand, shall be entitled to an equitable price adjustment for the work quantity actually performed, limited to a total payment not more than 75 percent of the amount originally bid for the item.

Payment for work occasioned by changes or alterations will be made in accordance with the provisions set forth under subsection 109.03. If the work is of sufficient magnitude as to require additional time in which to complete the project, such time adjustment may be made in accordance with the provisions of subsection 108.06.

104.03 Reserved

104.04 Maintenance of Traffic. Unless otherwise provided, the existing road while undergoing improvements shall be kept open to all traffic by the Contractor. Where so provided on the plans or in the special provisions, the Contractor may bypass traffic over an approved detour route or by approved part-width construction.

The Contractor shall keep the portion of the project being used by public traffic, whether it be through or local traffic, in such condition that traffic will be adequately accommodated. He shall also provide and maintain in a safe condition temporary approaches or crossings and intersections with trails, roads, streets, businesses, parking lots, residences, garages and farms; provided, however, that snow removal will not be required of the Contractor. He shall furnish and apply water or use other satisfactory means for dust control.

The Contractor shall bear all expense of maintaining traffic over the section of existing road undergoing improvement and of constructing and maintaining such approaches, crossings, intersections, and other features as may be necessary, without direct compensation, except as provided in (a), (b), and (c) below.

(a) Special Detours.-When the bid schedule contains an item for "Maintenance of Detours" or "Removing Existing Structures and Maintaining Traffic", then the payment for such item will cover all cost of constructing and maintaining such detour or detours, including the construction of any and all temporary bridges and accessory features and the removal of the same, and obliteration of the detour road. Right-of-way for temporary highways or bridges called for under this paragraph will be furnished by the Government.

(b) Maintenance of Traffic During Suspension of Work.— During any suspension, the Contractor shall make passable and shall open to traffic such portions of the project and temporary roadways or portions thereof as may be directed by the Engineer for the temporary accommodation of necessary traffic during the anticipated period of suspension. Thereafter, and until an issuance of an order for the resumption of construction operations, the maintenance of such a temporary route or line of travel, if done by the Contractor will be as directed, and will be paid for in accordance with subsection 109.04.

When work is resumed, the Contractor shall replace or renew any work or materials lost or damaged because of such temporary use of the project; shall remove to the extent directed by the Engineer any work or materials used in the temporary maintenance thereof by the Government and shall complete the project in every respect as though its prosecution had been continuous and without interferences. All work performed as directed during such suspensions, will be paid for by the Government at contract prices, agreed prices, or force account.

(c) Flagmen and Pilot Car Operators.-If the special provisions permit payment to be made in full or in part for the labor costs of flagmen and pilot car operators furnished with the prior approval of the Engineer, such payment will be made in accordance with subsection 109.04(a), excluding payment for foremen.

104.05 Rights in and Use of Materials Found on the Work. The Contractor, with the approval of the Engineer, may use on the project such stone, gravel, sand, or other material determined suitable by the Engineer, as may be found in the excavation and will be paid both for the excavation of such materials at the corresponding contract unit price and for the pay items for which the excavated material is used. He shall replace at his own expense with other acceptable material all of that portion of the excavation material so removed and used which was needed for use in the embankments, backfills, approaches, or otherwise. No charge for the materials so used will be made against the

Contractor. The Contractor shall not excavate or remove any material from within the highway location which is not within the grading limits, as indicated by the slope and grade lines, without written authorization from the Engineer.

In the event the Contractor has produced or processed materials from lands of the Government in excess of the quantities required for performance of this contract, the Government may take possession of such excess materials, including any waste material produced as a byproduct, without obligation to reimburse the Contractor for the cost of production, or may require the Contractor to remove such materials and restore the premises to a satisfactory condition at the Contractor's expense. This provision will not preclude the Government from arranging with the Contractor to produce material over and above the contract needs, payment for which will be by mutual agreement between the Government and the Contractor.

Unless otherwise provided, the material from any existing abandoned structure may be used temporarily by the Contractor in the erection of the replacement structure. Such material shall not be cut or otherwise damaged except with the approval of the Engineer.

104.06 Final Cleaning Up. Before final acceptance, the highway, borrow pits, and all ground occupied by the Contractor in connection with the work shall be cleaned by him of all rubbish, excess materials, temporary structures, and equipment; and all parts of the work shall be left in an acceptable condition. This work will be considered necessary work auxiliary to the accomplishment of the contract and no direct payment will be made therefor.

Section 105.-CONTROL OF WORK

105.01 Authority of the Engineer; Suspension of Work. The Engineer will decide all questions which may arise as to the quality and acceptability of materials furnished and work performed and as to the rate of progress of the work; all questions which may arise as to the interpretation of the plans and specifications; all questions as to the acceptable fulfillment of the contract on the part of the Contractor.

The Engineer's decision will be based on engineering judgment, taking into consideration all facts, the inherent variations in the processing and testing of highway materials, past experiences, research findings, and other factors bearing on

the issue, including all regulations, instructions, and guidelines established by the Government for administration of contract work. Such tests as the Engineer deems necessary may be taken to ascertain the degree of conformance of the material or work in question with the plans and specifications.

The Engineer will have the authority to suspend the work wholly or in part due to the failure of the Contractor to correct conditions unsafe for the workmen or the general public; for failure to carry out provisions of the contract; for failure to carry out orders; for such periods as he may deem necessary due to unsuitable weather; for conditions considered unsuitable for the prosecution of the work or for any other condition or reason deemed to be in the public interest. Suspension of work on some but not all items will be considered "partial suspension". Suspension of work on all items will be considered "total suspension". Work of an emergency nature ordered by the Engineer for the convenience of public traffic, and minor operations not affected by nor connected with the cause of suspension, if permitted by the Engineer, may be performed during a period of total suspension.

Any adjustment of contract time for suspension of work will be made as provided in subsection 108.06 and 108.09.

105.02 Plans and Working Drawings. Plans furnished by the Government will show lines, grades, typical cross sections of the roadway, location and construction details of all structures and a summary of items appearing on the bid schedule. Only general features will be shown for steel bridges. The Contractor shall keep one set of plans available at the work site at all times.

The plans shall be supplemented by such working drawings as are necessary to adequately control the work. Working drawings for structures shall be furnished by the Contractor and shall consist of such detailed plans as may be required to adequately control the work and are not included in the plans furnished by the Government. They shall include stress sheets, shop drawings, erection plans, falsework plans, cofferdam plans, bending diagrams for reinforcing steel or any other supplementary plans or similar data required of the Contractor. All working drawings must be approved by the Engineer, but it is mutually agreed that the Contractor shall be responsible for accuracy of dimensions and details and for agreement and conformity of his working drawings with the contract plans and specifications. This approval shall not operate to relieve the Contractor of any of his responsibility under the contract for the successful completion of the work.

Shop detail drawings and other working drawings shall not exceed 22 inches by 36 inches in size. Three sets of blue prints or other acceptable type copies shall be submitted to the Engineer for his purposes, one set of which will be returned to the Contractor with desired revisions noted thereon. After correction and approval, five additional sets of prints or copies shall be given to the Government. Upon completion of fabrication, the original tracings, or one set of reproducible prints or tracings, shall be furnished to the Government.

The contract price shall include the cost of furnishing all working drawings.

105.03 Conformity with Plans and Specifications. All work performed and all materials furnished shall be in reasonably close conformity (see definition) with the lines, grades, cross sections, dimensions and material requirements shown on the plans or indicated in the specifications.

Plan dimensions and contract specification values are to be considered as the target value to be strived for and complied with as the design value for which any deviations are allowed. It is the intent of the specifications that the materials and workmanship shall be uniform in character and shall conform as nearly as realistically possible to the prescribed target value or to the middle portion of the tolerance range. The purpose of the tolerance range is to accommodate occasional minor variations from the median zone that are unavoidable for practical reasons. When a maximum or minimum value is specified, the production and processing of the material and the performance of the work shall be so controlled that material or work will not be preponderately of borderline quality or dimension.

In the event the Engineer finds the materials or the finished product in which the materials are used not within reasonably close conformity with the plans and specifications but that reasonably acceptable work has been produced, he will then make a determination whether the work will be accepted and remain in place. In this event, the Engineer will issue a change order which will provide for an appropriate adjustment in the contract price for such work or materials as he deems necessary to conform to his determination based on engineering judgment.

In the event the Engineer finds the materials or the finished product in which the materials are used or the work performed are not in reasonably close conformity with the plans and specifications and have resulted in an inferior or unsatisfactory product such work or materials shall be removed and replaced or otherwise corrected by and at the expense of the Contractor.