Section 4188. Traffic Control Devices
1. Use crashworthy traffic control devices that meet MASH 2016 or NCHRP Report 350 as required. Upon request provide the following to the Engineer for the purpose of documenting the crashworthiness of temporary traffic control devices:
· The vendor’s self-certification for Category 1 devices.
· FHWA Eligibility Letter for NCHRP Report 350 Category 2 and Category 3 devices.
· FHWA Eligibility Letter for AASHTO MASH 2016 Category 2 and Category 3 devices.
2. FHWA Eligible Devices.
· NCHRP Report 350.
· MASH 2016.
3. Category 1 Devices.
a. Category 1 devices include cones, tubular markers, 42 inch channelizers, flexible delineator posts, and plastic drums without attachments.
b. After December 31, 2021 use only MASH 2016 compliant Category 1 devices. Category 1 devices may be “self-certified” by each Manufacturer as MASH 2016 compliant if there are no attachments to the devices.
4. Category 2 Devices.
a. Category 2 devices include Category 1 devices with attachments, barricades, and portable sign supports.
b. Category 2 devices that meet NCHRP Report 350 requirements may be used through December 31, 2024. After December 31, 2024 use only MASH 2016 compliant Category 2 devices.
5. Category 3 Devices.
a. Category 3 devices include temporary barriers, fixed sign supports, crash cushions, truck or trailer mounted attenuators, and other work-zone devices not meeting the definitions of Category 1 or Category 2 devices.
b. Category 3 devices that meet NCHRP Report 350 may be used through December 31, 2029. After December 31, 2029 use only MASH 2016 compliant Category 3 devices.
6. Category 4 Devices.
a. Category 4 devices include trailer-mounted devices (i.e. flashing arrow panels, temporary traffic signals, area lighting supports, and portable dynamic message signs.)
b. Currently, there are no Category 4 devices that meet MASH 2016 or NCHRP Report 350 requirements. Category 4 devices shall meet the requirements of the contract documents.
Furnish reboundable drum channelizing devices made for use in traffic control zones. Submit drum type, manufacturer, model, and size to the Materials Engineer for approval. Ensure channelizing devices meet the requirements of the MUTCD, Part 6, Section 6F.67 and the following requirements:
1. Drum body made from an impact resistant, flexible, and reboundable material that is highway orange meeting Federal Color Standards.
2. Material specifically formulated with ultraviolet stabilizers to provide satisfactory weatherability characteristics and resist fading.
3. Top of the body designed so that small signs can be securely affixed and stay attached upon impact.
1. Drums designed to allow a minimum of four horizontal, circumferential bands of 4 inch minimum width retroreflective sheeting.
2. The first (top) and third bands orange, and the second and fourth (bottom) bands white.
3. Nonreflectorized spaces between bands (if present) no wider than 2 inches.
4. Retroreflective sheeting for the bands meeting the requirements of Article 4186.03 and recommended by the manufacturer for use on drums.
1. Drums, when properly ballasted, are not to move, overturn, or separate due to air turbulence created by passing vehicles or moderate winds.
2. The ballast is to be of sand, recycled tire collar if applicable to the drum, or an Engineer approved material that will not present a hazard to motorists, workers, or pedestrians.
3. Apply the limitations specified in MUTCD Section 6F.67 for a drum weighted with ballast.
4. Anti-roll feature that prevents drums from rolling freely if overturned.
Comply with Materials I.M. 488.02 for inspection and acceptance of reboundable traffic control drums.
4188.03 ORANGE MESH SAFETY FENCE.
A. Meet the following material requirements:
1. Height of 48 inches ± 2 inches and constructed of orange plastic mesh containing ultraviolet stabilizers to prevent degradation.
2. Remain flexible down to 0°F.
3. Minimum tensile strength of 250 pounds per foot in the longitudinal direction and 150 pounds per foot in the vertical direction.
4. Maximum aperture opening of a nominal 4.5 square inches.
5. Maximum porosity of 55% for the safety fence surface area.
6. Available in rolls of at least 50 feet in length to minimize fence joints for an individual fence location.
B. Securely attach three horizontal nominal 1 inch bands of Type III or IV white retroreflective sheeting meeting the requirements of Article 4186.03 to the safety fence on the side facing traffic. Locate the bands at the mid-height and within 9 inches from the top and bottom of the fence fabric. Comply with Materials I.M. 488.03 for inspection and acceptance of orange mesh safety fence.
Furnish reboundable channelizing devices made for use in traffic control zones. Ensure channelizing devices meet the requirements of the MUTCD and the following requirements:
1. Channelizer body is made from an impact resistant, flexible, and reboundable material that is highway orange meeting Federal Color Standards.
2. Material is specifically formulated with ultraviolet stabilizers to provide satisfactory weatherability characteristics and resist fading.
1. Minimum of two orange 6 inch bands of Type VIII reflective sheeting and two white 6 inch bands of Type IV reflective sheeting.
2. Retroreflective sheeting for the bands meeting the requirements of Article 4186.03 and recommended by the manufacturer for use on drums.
3. The first (top) and third bands orange, and the second and fourth (bottom) bands white.
4. Nonreflective spaces between the bands no wider than 2 inches.
1. The channelizer, when properly ballasted, is not to move, overturn, or separate due to air turbulence created by passing vehicles or moderate winds.
2. The ballast is to be supplied by the manufacturer, is to weigh no less than 30 pounds, and is not to present a hazard to motorists, workers, or pedestrians.
3. Anti-roll feature that prevents channelizers from rolling freely if overturned.
Comply with Materials I.M. 488.04 for inspection and acceptance of channelizers.
4188.05 Temporary Lane Separator System.
A. General.
· The modular units interface with each other to form a continuous longitudinal channelizing system.
· The temporary lane separator system is designed to allow a radius or curve as required by roadway geometry.
· The complete system is NCHRP 350 or Manual for Assessing Safety Hardware (MASH) compliant. A copy of the FHWA approval letter may be required by the Engineer.
B. Curb Unit.
· Modular design that is fastened to or placed on the underlying pavement or bridge deck according to the manufacturer’s recommendations.
· Mountable design to allow for emergency vehicle crossovers.
· Minimum of one drainage scupper per unit or other drainage system to allow for cross drainage under or around the curb module with a maximum of 1 inch separation between individual curb units.
· Minimum length of 36 inches, maximum height of 4 inches, and maximum width of 12 inches.
· Yellow if used in a work zone installation or a permanent installation adjacent to yellow pavement markings, and white if used in a permanent installation adjacent to white pavement markings.
C. Upright Post.
· At least one upright post (manufactured from flexible plastic) for each modular curb unit.
· Posts uniformly spaced at no greater than 42 inches along the channelizing system.
· Posts orange in color if used in a work zone installation, yellow if used in a permanent installation adjacent to yellow pavement markings, and white if used in a permanent location adjacent to white pavement markings.
· Posts a minimum of 28 inches in height measured from the pavement or bridge surface, and a minimum of 2 inches in width facing traffic.
· Two 6 inch bands of Type IV retroreflective sheeting meeting the requirements of Materials I.M. 486.03 placed near the top of each post (top band located no more than 2 inches from the top of the post), with a maximum 4 inch space between the bands.
· White retroreflective sheeting if used in a work zone or permanent installation adjacent to a white pavement marking, and yellow retroreflective sheeting if used in a permanent installation adjacent to yellow pavement markings.
· Posts easily replaceable under traffic conditions.
D. Acceptance.
Comply with Materials I.M. 488.05 for inspection and acceptance of temporary lane separator systems.
4188.06 Temporary LED Floodlighting Luminaires.
Furnish luminaires made for portable, mobile self contained, floodlights for temporary traffic control zones. Luminaire shall have IES LM-79-08 report from qualified independent laboratory verifying luminaire performance, including the following requirements:
· L70 @ 25°C of 70,000 hours.
· LED color temperature of 4000 cct to 5000 cct.
· LED light engines meet dust and moisture rating of IP-66.
· Designed and tested to comply with ANSI C136.31 2001 for 100,000 cycles at 3G acceleration for normal and bridge applications.
· Surge protection for LED driver and electronics - category C high (20kV, 10kA).
· Totally enclosed glass refractor lenses with type IV distribution.
· IES glare control rating of "full cut off".
· Minimum initial output rating of 7200 lumens.
· Meets State of Iowa Energy Code requirements for LED roadway lighting (66 lm/W).
· Photoelectric controlled for dusk to dawn operation.
· Comply with Materials I.M. 488.06 for inspection and acceptance of Temporary LED Floodlighting Luminaires.
4188.07 PORTABLE DYNAMIC MESSAGE SIGN.
1. A PDMS is defined as all components working together to accomplish the requirements of the specifications. These components include, but are not limited to, LED pixel boards, on-board computer, cellular modem (when specified), trailer, mounting equipment, solar panels, batteries, charge controller, etc.
2. The message panel shall be trailer mounted.
Message panel shall be mounted at a height of at least 7 feet, measured from
bottom of sign to ground directly below. Sign presents a level appearance. Sign
is capable of displaying three lines of up to eight characters at one time.
Characters shall be configured using a 7 pixel tall by 5 pixel wide ratio font.
Characters shall be either yellow or orange and be displayed on a black
background. Message panel may be configured as character matrix, line matrix,
or full matrix.
3. PDMS (18 inch) shall have minimum 18 inch tall
characters as defined by NEMA TS-4-2016 with a character width of 12.5 inches
+/- 1.0 inch. Character spacing shall be 2.8 inches +/- 0.5 inch. This PDMS size
shall be used on all roadways except as allowed in Article 4188.07, A, 4.
4. PDMS (12 inch) shall have minimum 12 inch tall characters as defined by NEMA TS-4-2016 with a character width of 8.5 inches (+/- 1.0 inch). Character spacing shall be 1.7 inches +/- 0.5 inch. The overall size of the PDMS display panel shall not exceed 86 inches in width. This DMS size shall only be used on roadways where the speed is 40 mph or less when shown in the contract documents.
5. Message panel shall be visible from 1/2 mile under both day and night conditions. Letters shall be legible from 600 feet for nighttime conditions and 800 feet for normal daylight conditions. Message sign shall include automatic dimming for nighttime operation and a power supply capable of providing service for 7 continuous days without recharging.
6. Message panel controlled by an onboard computer capable of:
· Storing a minimum of 99 programmed messages for instant recall,
· Being programmed to accept messages created by the operator via an alpha-numeric keyboard, and
· Being programmed remotely by National Transportation Communication for Intelligent Transportation Systems Protocols (NTCIP) DMS software (when specified).
7. Physical access to the onboard computer protected by a padlock or other locking handle mechanism. Electronic access to the onboard computer protected by a username and password.
PDMS shall be equipped with a cellular modem for remote communications.
1. Cellular service provider shall have data coverage within project limits. Contractor shall be responsible for integrating cellular modem with the PDMS.
2. Cellular modem shall be capable of obtaining its location by GPS. Current location from GPS coordinates shall be stored in cellular modem’s memory for retrieval by NTCIP software. Modem shall have firewall security protections that only allow communications from specified IP addresses. Cellular modem shall not use default usernames or passwords.
3. Upon deployment of PDMS and confirmation that remote communication has been successfully setup; the following information shall be supplied to the Traffic Management Center (TMC) via email
at DOT-IWZ@iowadot.us for integration into the statewide ATMS software:
· IP address
· Port number (may not use default, 161)
· Protocol used (TCP or UDP)
· SNMP community name (may not use default names, i.e., “public” or “administrator”)
· Sign Number
· Latitude and Longitude Coordinates
· Route PDMS is on and direction of traffic flow that can view PDMS
Modem and PDMS credentials shall not be default values or recorded on any part of the trailer.
Upon relocation or removal of PDMS, send email to DOT-IWZ@iowadot.us, with the PDMS sign number and new location so it can be updated or released by the TMC’s software.
4. Typical monthly data usage by Contracting Authority is 5 Mb when PDMS is in good working condition. Additional data usage is possible if PDMS requires remote troubleshooting or maintenance.
PDMS onboard computer and operating firmware shall be compliant with at least NTCIP 1203 v1.15 supplemented with NTCIP 1203 Amendment 1 v07, (dated July 3, 2001) for the following commands:
· Read configuration data from sign,
· Send configuration data to sign,
· Poll sign (retrieve sign status) both manual and automated with software,
· Activate a message,
· Blank or remove a message,
· Upload fonts, and
· Reset controller/onboard computer.
4188.08 TEMPORARY PORTABLE RUMBLE STRIPS.
Furnish temporary portable rumble strips to be used in traffic control zones. Ensure temporary portable rumble strips meet requirements of MUTCD and the following:
1. Rated for posted speed limits up to 70 mph.
2. Installation without using nails or adhesive.
3. Provides auditory and tactile warnings for all vehicles.
4. Minimal lateral displacement under traffic loading.
5. Installation and removal of rumble strips in less than 5 minutes.
6. Reusable within manufacturer’s recommended life of the product.
Comply with Materials I.M. 488.07 for inspection and acceptance of temporary portable rumble strips.
4188.09 SPEED FEEDBACK SIGN.
Speed feedback signs shall be approved per Materials I.M. 488.09.
B. Power System.
C. Speed Display and Behavior.
D. LEDs.
E. Controls.
F. Operating Modes.
G. Radar.
H. Regulatory Sign.
4188.10 Arrow Boards.
A. General.
Arrow Boards shall be approved per Materials I.M. 486.12.
B. Power System.
C. Display.
D. Controls.
E. Operating Modes.
Following 4 modes are the minimum required. Additional modes are allowed, but not required.
F. Portable Dynamic Message Signs as an Arrow Board.
A portable dynamic message sign may be used to simulate an arrow board if it meets the requirements in this section.
4188.11 GPS and Remote Communications.