2528 Traffic Control

Section 2528. Traffic Control.

2528.01 DESCRIPTION.
This section describes various materials, equipment, and procedures involved in traffic control during construction. The Contractor and the Contracting Authority have certain responsibilities, whether public traffic is allowed or is prohibited during construction, and Article 1107.09 shall apply.

The contract may include an item for traffic control, in which case the Contractor shall furnish, erect, operate, maintain, move, and remove all traffic control devices required by the contract documents.

The contract may indicate that traffic control is incidental, in which case the Contracting Authority will furnish all signs and traffic control devices, except pilot car and flaggers' signs, and all Type III barricades, and mounting devices therefor, and the Contractor shall furnish all other traffic control devices required. The Contractor shall erect, operate, maintain, move, and remove all traffic control devices. Signs and barricades to be furnished by the Contracting Authority will be made available at a nearby maintenance site, and they shall be returned when no longer needed.

The contract documents may specify that orange mesh safety fence be used in conjunction with other traffic control devices as part of the project traffic control requirements. The orange mesh safety fence shall meet the requirements of Article 4188.03. The safety fence used in this situation shall be securely supported so the fence is in a vertical position without any sagging. The safety fence supports shall be placed and located so they are not a safety hazard.

All traffic control shall be in accordance with the current edition of the MUTCD, Part VI as adopted by the Department.

All Category I and Category II traffic control signs and devices used on Interstate and Primary Road projects shall meet National Cooperative Highway Research Program (NCHRP) Report 350. Category I devices are defined as low mass, single-piece traffic cones, tubular markers, single-piece drums, and delineators. No lights or signs may be attached to these devices in order for them to meet the Category I limitations. Category II devices are defined as vertical panels, Type I, II, and III barricades, and moveable skid mounted sign stands.

It shall be the responsibility of the Contractor to provide the vendor's self-certification for Category I devices and the FHWA NCHRP 350 approval memos for Category II signs and devices, to the Engineer to document crashworthiness of their Category I and II traffic control signs and devices. A list of approved Category II traffic control devices is found on the World Wide Web at the following URL: http://safety.fhwa.dot.gov/fourthlevel/hardware/wzd.htm.

Gender specific signs, such as FLAGMAN and MEN WORKING, will not be allowed. The signs shall either be neutral gender, as FLAGGER, or equivalent symbol signs. Control of traffic through work areas with flaggers shall also conform with the Iowa Flagger's Handbook, available from the Engineer.

A. Monitoring With Incident Response.
The Contractor shall provide 24 hour per day continuous monitoring of traffic control devices and incident response for emergency situations on projects during complex traffic situations as defined in the contract documents. The contract documents will identify projects requiring monitoring with incident response. A vehicle and operator shall be traversing the project throughout the entire traffic control zone at all times, except for refueling and short rest breaks no greater than 15 minutes in duration.

This work shall be furnished in accordance with the contract documents any time that signs, barriers, barricades, or other traffic control devices are in place during complex traffic situations.

The Contractor shall provide a vehicle and operator for this work as follows:

1. Equipment.
The vehicle shall be a 3/4 ton (or metric equivalent) pickup truck or another vehicle in good condition with adequate weight and power and suitably equipped to move stalled automobiles or pickup trucks. The vehicle shall carry the Contractor's insignia and shall be equipped with an amber revolving light or amber strobe light visible in all directions and a cellular telephone or similar type of mobile phone. The vehicle shall be capable of carrying traffic signs, tools, traffic control devices, and other necessary equipment. When used on projects where more than one lane in one direction is maintained at all times, this vehicle shall also be equipped with a Type C arrow panel as described in Article 2528.06 mounted to be visible to traffic approaching from behind.

2. Operation.
The Contractor shall furnish an operator for the vehicle. Defective devices shall be re-erected, repaired, or replaced by the operator immediately upon discovery. The operator and vehicle are to be available to assist persons with vehicle problems and to move automobiles, pickup trucks and other obstructions so as to keep all travel lanes and shoulders available for public traffic. Assistance to motorists and involvement with obstructions shall continue until they are no longer an impediment to traffic and further assistance can be provided safely by others. When a vehicle or anything else is obstructing a travel lane or shoulder intended to be clear, the operator shall assist the motorist or remove the obstruction promptly and safely. If further assistance is needed, it is to be summoned.

The operator shall keep a report of any events that restrict the normal traffic flow during complex operations, including responses to emergency situations, on forms provided by the Engineer. A copy of this report shall be provided to the Engineer daily.

The Contractor may be requested by the Engineer to operate project related Changeable Message Signs (CMS) for advance traffic notification and warning. Authority to operate CMS units will be under the direction of the Engineer according to the contract documents. Only the Engineer may add or modify any preprogrammed messages. The Contractor may only operate the CMS to display one of the preprogrammed messages.

During anticipated peak traffic times, the Engineer may direct the Contractor to provide additional monitoring personnel for CMS operation and other traffic monitoring functions.

B. Traffic Quality Control
The Contractor shall perform the following quality control work associated with monitoring and documenting traffic control conditions daily as the project is constructed:

1. Review all traffic control operations for compliance with contract documents and maintain a project traffic control daily diary, which shall be submitted to the Engineer and will become a part of the Contracting Authority's project records. The diary shall include:

a. all reviews of traffic control devices and operations,
b. approved changes to traffic control,
c. incidentals affecting the efficiency and safety of traffic,
d. a list of trained flaggers used on the project.

2. Monitor traffic operations and submit proposed Traffic Control Plan changes to the Engineer for approval.

3. Coordinate all changes to the Traffic Control Plan.

4. Coordinate all traffic control operations, including those of subcontractors and suppliers.

The Contractor shall have a technician on staff that has attended and passed the exam in an ATSSA Traffic Control Technician or International Municipal Signal Association (IMSA) Work Zone Traffic Control training class even though the Traffic Control portion of the contract may be subcontracted. This Traffic Control Technician shall be responsible for the overall management of the Contractor's quality control program for traffic control.

2528.02 SIGNS.
Signs shall be of the size and type shown in the contract documents and shall utilize retroreflective sheeting meeting requirements of Article 4186.03. Signs for traffic control zones in duration for 4 calendar days or more shall be mounted on fixed posts. Signs for traffic control zones in duration for less than 4 calendar days may be mounted on moveable skids or fixed posts. Fixed post mounted signs shall have the sign sheeting applied to rigid wood or metal and shall be mounted at a height of at least 7 feet (2.2 m), measured from the bottom of the sign to the near edge of the pavement. A secondary sign on the same post may be mounted 1 foot (0.3 m) lower than specified above. Post-mounted signs shall have a clear distance 2 feet (0.6 m) behind a curb or beyond the edge of the shoulder. Until January 2002, moveable skid signs may use sheeting applied to rigid metal or wood, or flexible roll-up sheeting. After January 1, 2002, moveable skid mounted signs shall use flexible roll-up sheeting or other skid mounted sign systems that meet NCHRP 350 requirements. Moveable skid mounted signs shall be mounted at a height of at least 1 foot (0.3 m) above the roadway.

Mounting devices shall not be so substantial as to be a hazard to vehicles. Posts mounted in existing soil shall meet the following requirements:

1. Wood sign supports meeting the materials requirements of Article 4164.04

2. U-shaped rail steel posts not exceeding 3.0 pounds per foot (0.3 m).

3. 2 1/4 or 2 1/2 inch (60 mm or 65 mm) square 12 gauge perforated steel tubing.

Dual-post and triple-post configurations using these sign supports are acceptable provided that no more than two posts occupy any 8 foot (2.4 m) wide path. Bracing of these posts will not be permitted. Posts exceeding these requirements shall have breakaway features approved by the Engineer.

Signs shall be in a condition so they are effective for the intended purposes when viewed from a vehicle. For nighttime installations, the reflectance shall be adequate so that the message is clearly readable. Signs shall be maintained in a near vertical position.

2528.03 CHANNELIZING DEVICES.
Channelizing Devices shall be of the type shown in the contract documents and shall utilize reflective sheeting meeting the requirements of Article 4186.03.

A. Barricades.
When Type I or Type II Barricades are furnished as one of the options for channelizing devices in lieu of vertical panels, 42 inch (1050 mm) channelizers, cones, or drums, a 2 foot (0.6 m) minimum length barricade may be used.

Type III barricades shall have a minimum length of rail of 6 feet (1.8 m). When traffic is permitted in each direction around a Type III Barricade, the Type III Barricade used shall have fully reflectorized faces on both sides of the rails.

Barricades shall be erected in essentially a horizontal position perpendicular to the direction of approaching traffic. They shall be ballasted so as not to cover any striped rail.

B. Cones, Vertical Panels, 42 Inch (1050 mm) Channelizers, Drums, and Tubular Markers.
Cones, vertical panels, 42 inch (1050 mm) channelizers, drums, and tubular markers shall meet the current requirements of the MUTCD, and Section 4188.

When used to separate two way traffic, temporary no passing lines shall be separated by approximately 16 inches (400 mm), with the marker to be installed between these lines.

Tubular markers shall be between 28 inches (710 mm) and 34 inches (750 mm) in height with a diameter facing traffic at least 2 inches (60 mm) in width. Tubular markers shall be completely faced with reflectorized white and orange sheeting. The white reflectorized sheeting shall be in two bands 4 inches (100 m) wide with 6 inches (150 mm) between bands. The top band shall be no more than 2 inches (50 mm) from the top of the tubular marker.

2528.04 PILOT CARS.
Pilot cars shall be pickup trucks or automobiles displaying the Contractor's company insignia, equipped with G20-4 signs reading: PILOT CAR - FOLLOW ME. Two signs shall be mounted on the vehicle so as to be clearly visible from both directions of traffic. The bottom of the signs shall be mounted at least 1 foot (0.3 m) above the top of the vehicle's roof.

Pilot cars shall be operated such that they maintain a uniform speed through the work area, no greater than 40 miles per hour (65m/hr).

2528.05 TEMPORARY BARRIER RAIL.
Temporary barrier rail shall be as shown in the contract documents. Unless otherwise shown, they shall be precast concrete units. The units shall be tied together as specified or as approved by the Engineer.

2528.06 LIGHTING DEVICES.
Lighting devices shall be furnished as required by the contract documents. Type A barricade warning lights will normally be required for nighttime installations. Type B warning lights will normally be required for 24 hour operation.

All barricade warning lights shall be in accordance with the ITE Standard for Flashing and Steady Burn Barricade Warning Lights and shall be identified as specified therein. In addition, Type A barricade warning lights shall operate on a 12 volt battery system, unless the ITE identification specifically indicates that the rating is based on a different system.

When arrow displays are used, they shall be Type C arrow displays described in the current edition of the MUTCD, Part VI, and they shall be operated in a sequential chevron mode when indicating a lane change.

2528.07 TEMPORARY TRAFFIC SIGNALS.
Traffic signals shall be as shown in the contract documents and shall be adjusted and operated as required therein. Details for traffic signals are in Part IV of the MUTCD. The minimum diameter lens shall be 12 inches (300 mm). Posts shall meet requirements of Article 2528.02.

All temporary traffic signal heads shall be equipped with backplates. The backplate shall provide a minimum of 5 inches (125 mm) black field around the signal assembly and shall have a dull black finish.

The Contractor shall furnish actuated signal controllers.

A signal operator shall be used to control temporary traffic signal installations being used for signalized equipment crossings. This operator shall be positioned with good sight distance for both the mainline and haul road.

2528.08 TEMPORARY FLOODLIGHTING.
Floodlighting shall be installed and in service before work is started that requires nighttime traffic control by the traffic control plan.

Luminaires used for floodlighting shall be standard roadway types with totally enclosed refractors. The Illuminating Engineering Society (IES) glare control rating shall be "cut off". The lamps shall have an initial output rating of 19,000 lumens or greater, for operation in such luminaires. All luminaires shall be approved by the Engineer.

Temporary floodlighting shall consist of either a pole-mounted luminaire or a luminaire mounted on portable equipment. The mounting height of luminaires shall be not less than 35 feet (11 m) above the roadway, and as shown in the contract documents. The Contractor shall determine pole length by field measurement to obtain specified mounting height. Poles shall be placed outside the normal shoulder line at the approximate locations shown in the contract documents.

Above ground lighting circuits shall be aluminum or A.C.S.R. triplex. Underground lighting circuits shall be type U.S.E. or U.F. All luminaires shall be photoelectric controlled for dusk to dawn operation.

The Contractor shall exercise reasonable care to avoid interruptions during the hours of darkness, shall repair promptly any damage to the system, and shall replace all burned out lamps as soon as possible.

2528.09 TEMPORARY ATTENUATORS.
Attenuators shall be constructed as shown in the contract documents. Unless otherwise specified, the Contracting Authority will furnish attenuators as indicated. The Contractor shall pick them up at a nearby maintenance site and shall return them in usable condition when no longer needed.

The Contracting Authority may also stock replacement parts for attenuators. When damaged, the Contractor shall install replacement parts or a new attenuator, and the Contractor shall replace parts that are damaged.

2528.10 FLAGGERS.
The flaggers shall be trained about safe flagging operations that comply with Iowa DOT Flaggers Handbook, Part VI of the MUTCD, and the Standard Specifications prior to flagging operations. Training of flaggers shall include the following:

1. Issue and review the current Iowa DOT Flaggers Handbook,
2. Presentation of the current Iowa Professional Flagging Video,
3. Issue flagger training card, which shall include the following:

Employee name,
Date of training,
Name of Instructor,
Expiration date of December 31 of the year following the training date.
The flaggers shall carry their flagger training card at all times and show it upon request.

4. Contractor shall maintain a list of the flaggers trained and the date of the training.

Training shall not be required for short time, emergency, or relief assignment of employees to flagging operations. Payment will not be made in accordance with Article 2528.12, A, 7.

Except in an emergency, flaggers shall use signs as specified in the current edition of the MUTCD, Part VI, except the signs shall be as least 24 inches (600 mm) wide. The sign shall be mounted on a staff with a clear distance of 6 feet (1.8 m) above the road surface.

To be visible to traffic while flagging, the flagger shall wear a soft cap or a hard hat and a vest, shirt, or jacket. The colors of these articles of dress shall be orange or strong yellow-green, or fluorescent versions of these colors. Combinations of these colors are acceptable.

2528.11 LIMITATIONS.
All traffic control devices subject to movement by wind shall be anchored by sandbags.

When a two way road is open to public traffic during contract work, one way traffic shall not be controlled through the work area by means of a carry through flag or other token, except during equipment failure or emergency. When voice or signal communication between flaggers at control points is difficult or not effective because of distance, sight, or noise, other means shall be used. These may be two way radio, pilot cars, or traffic signals. When the normal work area exceeds 1/4 mile (0.4 km) on Primary projects, pilot cars shall be used; however, where necessary for short durations, the distance may be extended to 1/2 mile (0.8 km) for better sight distance or to clear intersections or other safety considerations with approval of the Engineer, provided a two way radio is used for communication between flaggers.

During non-working hours, traffic control devices intended for working hours only shall be removed, covered, or turned down. When traffic control devices are no longer needed, they shall be removed.

During daylight hours, workers exposed to traffic in or adjacent to traffic lanes, should wear a vest, shirt, or jacket equal to that required for flaggers according to Article 2528.10.

At night, workers shall wear clothing that is similar in color to that required for flaggers and is retroreflective to be highly visible to drivers. The retroreflective clothing shall be designed to identify clearly the wearer as a person and shall be visible through the full ranges of body actions.

The Engineer may require traffic control devices to be recleaned by washing. The device shall be washed with a brush and water, and with detergent or solvent as necessary. Washing shall include a supplemental or auxiliary sign, if any, the entire target area or sign face, all reflectors, and faces of warning lights which are part of that device.

Entry to and exit from work areas shall be in the direction of public traffic and shall not cross open traffic lanes at other than designated locations. During hours of darkness, the Contractor shall operate equipment in the traffic control zone facing in the direction of traffic flow unless otherwise specified in the Traffic Control Plan. Darkness will include the period from sunset to sunrise and other times when conditions such as fog, snow, sleet or rain provide insufficient lighting to clearly identify persons and vehicles on the highway at a distance of 500 feet (150 m) ahead.

Unless otherwise stated in the traffic control plan, the Contractor shall provide for a minimum of 2 miles (3 km) between traffic control zones on rural roadways. Minimum distances between traffic control zones on urban roadways shall be at the direction of the Engineer.

2528.12 METHOD OF MEASUREMENT.

A. When the contract documents include an item for traffic control, the Engineer will measure for payment the following items:

1. Traffic Control.
This item will be the lump sum for traffic control for the project in addition to the following items.

2. Temporary Barrier Rail.
The Engineer will calculate the length of temporary barrier rail used based on count and the nominal length of each unit. The length of temporary barrier rail measured will be the length required per setup. Measurement will also be made for temporary barrier rail moved within, or added to, an existing setup when required by the contract documents. Measurement of temporary barrier rail, after its initial placement, will not be made unless it is required by the contract documents to be moved.

3. Temporary Attenuators.
The Engineer will count each temporary attenuator installed or reinstalled as required.

4. Temporary Traffic Signals.
The Engineer will count each group installation of temporary traffic signals operated by a common control unit. A group installation is normally four signal heads at the same traffic conflict area.

5. Temporary Floodlighting.
The Engineer will count each Temporary Floodlighting Luminaire installed.

6. Pilot Cars.
The Engineer will count the number of days each pilot car was used.

For a pilot car to be counted:

a. The pilot car must be needed and used as part of preplanned work that is started that day and is intended to proceed for a major part of the day. If used less than 4 hours, the operation will be counted as a half-day.

b. Other pilot cars must be needed and used for at least 1 hour during the day, perhaps intermittently, and this must be the primary duty of the employee. If used less than 4 hours, the pilot car will be counted as a half-day.

Short time, emergency, or relief assignment of employees to pilot car operations will not be counted separately.

7. Flaggers.
The Engineer will count the number of days each flagger was used.

For flaggers to be counted:

a. The flaggers must be needed and used as part of preplanned work that is started that day and is intended to proceed for a major part of the day. If used less than 4 hours, the flagger will be counted as a half-day.

b. Other flaggers must be needed and used for at least 1 hour during the day, perhaps intermittently, and this must be the primary duty of the employee. If used less than 4 hours, the flagger will be counted as a half-day.

Short time, emergency, or relief assignment of employees to flagging operations will not be counted separately.

8. Monitoring With Incident Response.
Monitoring with Incident Response will be measured in calendar days based on the contract quantity. Additional personnel required by the Engineer to provide additional traffic monitoring of CMS operation will be measured in calendar days per person needed.

B. When traffic control is incidental to other items on the project, and the following items are required, these will be items in the contract documents with measurement as follows:

1. Traffic Control.
No separate measurement will be made.

2. Temporary Barrier Rail.
Article 2528.12, A, 2, shall apply.

3. Temporary Attenuators.
Article 2528.12, A, 3, shall apply.

4. Temporary Traffic Signals.
Article 2528.12, A, 4, shall apply.

5. Temporary Floodlighting.
Article 2528.12, A, 5, shall apply.

6. Pilot Cars.
Article 2528.12, A, 6, shall apply.

7. Flaggers.
Article 2528.12, A, 7, shall apply.

2528.13 BASIS OF PAYMENT.

A. When the following items are required for traffic control, there will be items included in the contract documents with payment as follows:

1. Traffic Control.
When there is a contract item for Traffic Control, the Contractor will be paid the lump sum contract price. This payment shall be full compensation for erecting, maintaining, moving, and removing all traffic control devices required by the contract documents, including warning lights, and for furnishing all materials, labor, and equipment. This payment shall also be full compensation for traffic quality control.

2. Temporary Barrier Rail.
For the number of linear feet (meters) of temporary barrier rail measured, the Contractor will be paid the contract unit price per linear foot (meter).

3. Temporary Attenuators.
For each attenuator installed, the Contractor will be paid the contract unit price. For installing replacements and for furnishing replacements for attenuators, damaged by public traffic, the Contractor will be paid as extra work in accordance with Article 1109.03, B.

4. Temporary Traffic Signals.
The Contractor will be paid the contract unit price for each group installation operated by a common control unit, normally four signal heads at the same traffic control area. This payment shall be full compensation for the controller, signal heads, traffic detection system, and signal operator.

5. Temporary Floodlighting.
The Contractor will be paid the contract unit price for each Temporary Floodlighting Luminaire installed. This payment shall be full compensation for furnishing, installing, maintaining and servicing the temporary floodlighting units, all costs for electrical energy, and the cost of removing all lighting materials from the construction site.

6. Pilot Cars.
For the number of days each pilot car was operated, the Contractor will be paid the predetermined contract unit price per day.

7. Flaggers
For the number of days each flagger was used, the Contractor will be paid the predetermined contract unit price per day. This payment will be full compensation for providing trained flaggers in accordance with Article 2528.10.

8. Monitoring With Incident Response.
For the number of calendar days that Monitoring With Incident Response is used, the Contractor will be paid the contract unit price per calendar day. This payment shall be full compensation for furnishing the necessary vehicle (including operation, maintenance, and supplies); furnishing the operator; documentation of any events that restrict the normal flow of traffic including responses to an emergency situation; re-erecting, repairing, or replacing traffic control devices; providing assistance to persons with vehicle problems; moving stalled vehicles; and summoning further assistance when needed.

For the number of calendar days that additional personnel, such as for CMS operation, required by the Engineer are used, the Contractor will be paid the contract unit price per calendar day. This payment shall be full compensation for furnishing the required personnel and necessary support vehicles.

B. When traffic control and traffic quality control are incidental to other items on the project, and the following items are required, they will be included in the contract documents with payment as follows:

1. Traffic Control.
No separate payment will be made.

2. Temporary Barrier Rail.
Article 2528.13, A, 2, shall apply.

3. Temporary Attenuators.
Article 2528.13, A, 3, shall apply.

4. Temporary Traffic Signals.
Article 2528.13, A, 4, shall apply.

5. Temporary Floodlighting.
Article 2528.13, A, 5, shall apply.

6. Pilot Cars.
Article 2528.13, A, 6, shall apply.

7. Flaggers.
Article 2528.13, A, 7, shall apply.

When the Engineer requires recleaning of reflectorized surfaces of traffic control devices, payment will be made as extra work in accordance with Article 1109.03, B.

All traffic control devices furnished by the Contractor shall remain the Contractor's property at the completion of the work and shall be removed from the site when no longer needed.