Presentation on theme: "PORTABLE TRAFFIC MONITORING SITE INSTALLATION AND INSPECTION TRAINING"— Presentation transcript:
1 PORTABLE TRAFFIC MONITORING SITE INSTALLATION AND INSPECTION TRAINING PRESENTED BY:FLORIDA DEPARTMENT OF TRANSPORTATION AND SOUTHERN TRAFFIC SERVICESRUBIE FRASE & TERRY ROBINSON
2 THE IMPORTANCE OF DATA COLLECTING The State Road Department started collecting traffic data at ten locations back in As the state grew both in population and number of lane miles, the need to expand traffic data collection was obvious.
3 THE IMPORTANCE OF DATA COLLECTING The value of good traffic data became apparent early on in the evolution of the national Department of Transportation (DOT) and eventually the Federal Highway Administration (FHWA).
4 THE IMPORTANCE OF DATA COLLECTING This data is translated into revenue allocations for the state and federal highway programs.
5 THE IMPORTANCE OF DATA COLLECTING Good data is a result of good site installations. Good count/speed/vehicle classification and weight data is essential to the following customers:Some Internal Uses:Roadway Design uses our data to determine if facility enhancements/lane additions are needed;Pavement Design uses our data to determine pavement type & thickness requirements;Traffic Operations/Maint. Use it to determine lane closure restrictions. And there are many others.
6 THE IMPORTANCE OF DATA COLLECTING Data uses (cont.)Some External Uses:The FHWA compiles data for use in national trend reports, national Truck Weight Study and other studies and for apportioning funds back to us;Advertisers and developers that need to know how many motorists are passing a given location in order to set sign and rates or determine potential demand for retail outlets, etc. (among many others).
7 THE IMPORTANCE OF DATA COLLECTING Two categories of traffic monitoring sites have permanent equipment physically located in the roadway. These are TTMS and PTMS. They are the backbone of the traffic count program administered by the FDOT Central and District Offices.
8 THE IMPORTANCE OF DATA COLLECTING The data collected at these sites may include: volume, speed, vehicle class and weight. The type of equipment installed and the programs set-up in the equipment determine how the site functions.
10 TELEMETERED TRAFFIC MONITORING SITE TTMSTELEMETERED TRAFFIC MONITORING SITETTMS sites are the locations that are polled via modem daily by the TRANSTAT Central Office computers. They record and transmit every day of the year and provide the data used for adjusting short-term traffic counts to Annual Average Daily Traffic (AADT).TTMS sites are installed and maintained out of Central Office in Tallahassee.Many have solar panels
11 TYPE III PEDESTAL MOUNTED PTMSTYPE II BASE MOUNTEDTYPE III PEDESTAL MOUNTED
12 PORTABLE TRAFFIC MONITORING SITE PTMSPORTABLE TRAFFIC MONITORING SITEPTMS locations are usually installed on high volume urban arterials where rubber hose counts or other equipment is difficult to install and maintain.
13 PTMSPiezoLoopThe permanent part of the installation is the cabinet and loop/piezo wires installed in the pavement. Greater reliability, personnel safety, and accuracy are the reason loops and piezos are preferred to hose counts.
14 PTMSLOOPPIEZOLoops provide a volume count of vehicles crossing the loop sensors. The piezos provide classification count which measures the axles as the vehicle crosses the piezo.
15 PTMSTo gather data, a traffic counter is normally placed in the cabinet and attached to the wire harness for a short period (2 – 7 days) either annually or quarterly, then moved from one site to another, hence the term portable traffic monitoring site.
16 ADR-1000 COUNTER IN CABINET PTMSADR-1000 COUNTER IN CABINET
17 HISTORY OF ISSUES Issue – PTMS Inspections Not Passing Resolution – Train DOT, Construction, Contract and Sub-contract employees on how to install a PTMS site.
18 OBJECTIVE FOR THIS CLASS Above all, the need to follow Design Standards and Plan Specifications.Design standards are reviewed every year and changes made as needed. You need to keep a copy of the latest standards with you at all times.The following slide reflects a major change to loops.
20 OBJECTIVE FOR THIS CLASS Above all, the need to follow Design Standards and Plan Specifications.Review the plans and follow the placement, materials to be used and location precisely.For Example: Loops are no longer to be cut at a 45° angle. Since the year 2001 the standard is to drill corners with a 1.5” bit by 2” minimum depth.
21 OBJECTIVE FOR THIS CLASS Above all, the need to follow Design Standards and Plan Specifications.Loops SHOULD NOT be cut across the concrete joint in the roadway. As the vehicles travel across the pavement, the pavement jars and could loosen the loop wires and render them useless.
23 OBJECTIVE FOR THIS CLASS Above all, the need to follow Design Standards and Plan Specifications.Piezos come with a warranty card. The warranty card must be filled out and a copy of it placed in the cabinet along with a copy of the cabinet schematics.
25 OBJECTIVE FOR THIS CLASS Above all, the need to follow Design Standards and Plan Specifications.The difference between a good and bad site!Good Bad
26 OBJECTIVE FOR THIS CLASS Above all, the need to follow Design Standards and Plan Specifications.Every time a site does not pass on the first inspection is wasted tax payer’s money. This affects all of us including you.
27 GOING FORWARDThe plans are delivered to the Data Collection Manager, and they review them for proper location, design and placement.
29 GOING FORWARDThe Data Collection Manager shall be contacted by the contractor and/or sub-contractor prior to any installation. This includes the cabinet, loops and piezos.
30 GOING FORWARDThe Data Collection Manager shall be contacted when the site has been installed and ready for inspection.In most cases, there is a bonus tied to the project. If the site does not pass….your company may lose or be the cause of any bonus not being paid.
31 GOING FORWARDIn your travels throughout the district, if you find a damaged site, please do the following:Take a picture of the damage.Call Road Rangers or local police if the site was involved in an accident.Contact the Data Collection Manager immediately.In most cases, if the damage was caused by an accident, we can recoup the cost of repair from the at-fault insurance company.
32 CONTACT INFORMATIONRUBIE FRASE – I am the main contact person for District 5– OfficeCell
35 PRE-ENGINEERING PLANNING Sites are selected by the Data Collection and Planning Office in most scenarios.Sites are approved by the District Engineers.Plans are developed by the Office of Design and reviewed by the Data Collection Office.
36 PRE-ENGINEERINGPTMS sites are independent of one another, and sites are built to fit the location.Numerous departments are involved with the building of a PTMS site. Statistics office, Planning office, Data office, Design office, Engineering office, Construction division, etc.
37 PRE-ENGINEERING Utility locates are completed Pavement is cured and ready for sensorsAll equipment is on hand and meets Approved Product List (APL) and Qualified Product List (QPL)
38 PRE-ENGINEERING Engineers have approved ALL Plans and changes Schedules have been approved by: Project Manager, Project Engineer, Traffic Operations Engineer, ConsultantMaintenance of Traffic Plan submitted and Approved.
39 WHAT ARE THE COMPONENTS OF A PTMS SITE? MATERIALSCabinet – Type III, IV, and VPiezoelectric sensorsInductive Loop sensorsPull boxesGrounding electrodesSurge ProtectionConduit
40 MATERIALS Is cabinet in place? Does cabinet face the right direction? Does cabinet meet plans and specifications?Pull boxes in place and installed to specifications?All conduits in place?Have piezo sensors been tested prior to installation
41 MATERIALS Do loop wires and cables meet QPL? Are epoxies and sealants approved?Are dates on piezos, sealants and epoxies recorded?
42 ACTION Areas of Concern Maintenance of Traffic (MOT) Review of MOT PlanPlacement of Temporary Traffic Control DevicesAny ADDITIONAL SIGNS REQUIRED?District or Area Public Information Office Contacted?
43 ACTIONVerify all Public Safety and Local Governments are aware of Lane ClosuresUpdate Traffic Operations if changes are made to MOT PlanNotify ALL parties that all lanes are open upon completion
45 INDUCTIVE LOOP ASSEMBLIES Inductive loops are simply a coil of wire embedded in the road’s surface.The loops that are installed in the State of Florida and used by the FDOT are usually 6’ X 6’ loops using 12 gauge wire consisting of 4 turns.2 loops are installed in each lane that work in conjunction with the Piezoelectric Sensors.
46 INDUCTIVE LOOP ASSEMBLIES What is an inductor?An inductor is simply a coil of wire or an electromagnet.The inductor or wire has a very low resistance. When a vehicle passes over the loop, the inductance is elevated. This unit of increase is measured in “Henry’s”, or microhenries. The vehicle becomes the “inductor” or the coil.
47 LAYOUT OF SENSORS Verify the space of the sensors Standard spacing is 16 feet from leading edge of leading loop to leading edge of trailing loopLoops MUST be in CENTER of lane and MUST NOT cross expansion joints unless approved by Engineer prior to installations
48 LAYOUT OF SENSORSStandard loops are 6 foot by 6 foot, 4 turns on each loopLoops cut in asphalt SHALL be cut to a depth of 3 inches or deeperLoops cut in concrete SHALL be cut 2.5 inches or deeperPiezo Sensors shall be placed on one side of the lane and NOT placed in the middle of the lane
50 LOOPS & LOOP INSTALLATIONS Loops shall be installed as per FDOT Standards and SpecificationsFDOT District 5 Standards REQUIRE that LOOPS ARE NOT TO BE SPLICEDLoop wires are to be checked prior to installationLoops are to be placed in the BOTTOM of the slots
51 LOOPS & LOOP INSTALLATIONS Insure there are not any scars, rips, insulation abrasions, or kinks in the wire assemblyAll loops will be DRILLED in the corner using a 1.5 inch diameter bitMake sure slots are clear of debris, rocks, and asphalt depositsVerify depths are uniform throughout the entire cut
52 LOOPS & LOOP INSTALLATIONS No loops shall be installed in WET asphalt or concreteDo not apply sealants if roadway has residue or moisture in slots or on surface around cutsA minimum of 2 inches of clearance from the top of the loop wire in the slot to the surface of the roadway is required
53 LOOPS & LOOP INSTALLATIONS Loops shall be twisted a minimum of 6 to 12 turns per foot throughout the entire homerun lengthLoops shall be marked in pull box and inside the cabinetHomeruns shall be placed in the bottom of each cut
54 LOOPS & LOOP INSTALLATIONS The homerun cut will start at 3 inches deep and for each additional homerun added to the slot and additional ½ inch will be cut to the depthThis process will allow for fewer homerun cuts to the roadway
56 LOOPS & LOOP INSTALLATIONS We test all loops upon final inspectionWe are checking the insulation, signal strength and circuit of the loopsWe WILL NOT pass any loop that does no meet Entire Minimum Specifications
57 PIEZO INSTALLATIONSPiezoelectric sensors most commonly used by FDOT are Measurement Specialties Incorporated (MSI) – BL RoadtraxSensors – BL is short for Brass Linguini
59 PIEZO INSTALLATIONSPiezoelectric systems use piezoelectric sensors. The sensors are embedded in a conducting material. When weight is applied the pressure changes the voltage of the electric charge flowing through the conductor. The sensors measure the change in voltage and calculate the load.
60 PIEZO SENSORSThe base technology is piezoelectric polymer. The Brass Linguini is a highly compressed piezoelectric polymer in a coaxial configuration, with brass outer casing.The BL is flat, about 1/16” (1.5mm) thick and ¼ “ (7mm) wide. The sensors are put into the road in a ¾” (19mm) wide and 1.5” (25mm) deep slot cut in the road.
61 PIEZO SENSORS Installations Piezo sensors are to be installed to Manufacture SpecificationsAll warranty cards and manufacture paperwork shall be left in the cabinet upon installationAll testing of sensors are to be performed in front of a Representative of the FDOT
62 PIEZO SENSORS Installations Epoxies to be used are as follows: AS475: asphalt, modified mixes, superpave roadwaysG100-EBOND: concreteNO SPLICING OF PIEZO SENSORSAll piezo sensors MUST be marked in each pull box and inside of cabinet
63 PIEZO SENSORS Installations Re-test all piezo sensors in cabinet ***Piezo sensors shall be pushed down to .250 inches below surface of roadway*** This is a NEW application in FDOT Standards!!!
64 PULL BOX AND CONCRETE APRONS Pull boxes may be made of Quazite material or concrete with a steel lidAll pull boxes must have locking bolts and screwsEach pull box is required to have a concrete apron that is 12 inches off each edge, 4 inches deep and slopes away to the surface around the pull box
65 PULL BOX AND CONCRETE APRONS Pull boxes shall have a minimum of 8 inches of washed gravel inside of the baseAll pull boxes shall have clearly marked cables and conduits
66 CABINETS All cabinets should meet the Specifications on the plans All cabinets shall be mounted 48 inches off the ground measured to the handle of the cabinet to groundThe cabinet shall have proper grounding and grounding electrodes in place
67 IN-ROAD SENSOR TEMPLATES The most common configuration used is the Loop-Piezo-Loop.Piezo-Loop-Piezo configurations are also used in some scenarios.WIM or Weigh in Motion sites most commonly use Piezo-Loop-Piezo configurations.
68 IN-ROAD SENSOR TEMPLATES PTMS sites that collect volume and speed only by lane are made up of loop-loop configurations.The type of sensors to be installed will be determined by the appropriate parties and placed in the design plans.
69 SITE LAYOUT AND MEASUREMENTS Determine where the Piezo sensor will be placed in the lane.Piezos are always laid perpendicular to the lane.Mark the line with crayon or paint using a straight edge.Add 6 inches to the length of the piezo to insure the length is correct.
70 SITE LAYOUT AND MEASUREMENTS The piezo MUST BE located between the loops in the travel lane.Measure upstream from the piezo 5 feet and mark this spot with crayon or paint.Measure from the piezo 11 feet and mark with crayon or paint.Using the center point we have already determined, we will now layout the loop.
71 SITE LAYOUT AND MEASUREMENTS The loop is marked and painted.Using a steel tape we will now measure 16 feet downstream and make a mark, this is the leading edge for the trailing loop. We will now measure 22 feet from the leading loop (this is 6 feet behind the mark we just made). We now have the second loop ready to mark and paint.
72 SITE LAYOUT AND MEASUREMENTS We will use a straight edge that is at least 6 feet long to mark each leg of the loops.A Laser may also be used to insure the loops are parallel in the lane.We now have a loop-piezo-loop configuration.
73 SITE LAYOUT AND MEASUREMENTS Check the loops from the stripe using a steel tape, each loop should be the same distance from the edge line or skip line, if not check the measurements and adjust until the distances are the same.See diagrams for reference.
74 CONSTRUCTION CHECKLIST - PIEZOS Type I or IICable length of piezo sensorsApproved Epoxy on Approved Products ListDepth of saw cut – 7/8” – 1.25” to 1.5”Width of saw cut – ¾” – 7/8”
75 CONSTRUCTION CHECKLIST - PIEZOS Piezo tested prior to installationsWarranty cards filled out completelySlots clean of debris and waterEpoxy mixed to manufacturer’s standardDuct tape applied to each side of piezo cut
76 CONSTRUCTION CHECKLIST - PIEZOS Epoxy poured in several lifts or layersSensor cables at correct depthSensors retested after epoxy is appliedManufacturer install sheets completedCables marked with lane of piezo
77 CONSTRUCTION CHECKLIST - LOOPS Loops are corrected cut and corners drilled.Loops are cut at correct depthLoop wire is 12 gauge wire that is gasoline and oil resistantLoop wire is placed into bottom of slot, no visible kinks or knots in wire
78 CONSTRUCTION CHECKLIST - LOOPS Wire is applied with a blunt object (not a screwdriver, knife, etc.)Loop wire is turned 4 times in gridLoop wire is continuous with no splices in roadwayLoop slots are clean and compressed air used to blow out slotsLoop slots are dry
79 CONSTRUCTION CHECKLIST - LOOPS Loop wire is placed in slot only when all saws and blowers are no longer in useLoop wires are twisted at homerun junction – 6-12 twists per footWire is re-inspected for cuts, nick, knots.
80 CONSTRUCTION CHECKLIST - LOOPS Wire is placed into conduit and gently pulled to pull boxes.Loop wires are marked in pull box and coiled with inches of excess wireWire is tested for inductance and continuity
81 CONSTRUCTION CHECKLIST – PULL BOXES Pull box meets specificationPull box is placed in solid groundPull box has correct depth of washed gravelPull box has a 5’ concrete pad surrounding itPull box is level and allows water to run off and not collect in or on pull boxGrass and aggregates are placed around pull box to prevent erosion
82 CONSTRUCTION CHECKLIST - CABINETS Cabinet should meet SpecificationsCabinet should be securely anchoredCabinet should be properly groundedCabinet should be mounted with the center of the cabinet at 48” from the groundCabinet should be facing away from the roadway
83 PTMS CHECKLIST Are piezo lengths correct? ______ Are piezo cables long enough to reach the cabinet? ______Is the epoxy being used approved and mixed properly? ______Is loop wire 12 gauge and gasoline and oil resistant? ______Are loops located in the center of the lane? ______
84 PTMS CHECKLISTHave piezos been checked prior to placement in road? ______Has warranty card and paperwork been completed? ______Is roadway clean and all equipment turned off before sensors installed? ______Are saw cuts clean and is depth the same throughout entire loop/piezo? ______Are corners of loops drilled with a 1 1/2” bit? ______
85 PTMS CHECKLISTDo loop wires lay in bottom of slots without rise and falls? ______Is loop wire twisted at homerun intersection? ______Do loop wires have any kinks or cuts? ____Is loop sealant applied evenly and covers all the slots? ______Is the excess loop sealant removed from the roadway? ______
86 PTMS CHECKLIST Is epoxy mixed correctly? ______ Is epoxy on the APL list? ______Was the piezo epoxy applied in layers? ___Is epoxy cured and dry? ______Is loop wire labeled? ______Are pull boxes approved? ______Are pull boxes correctly installed? ______Washed gravel in pull boxes? ______
87 PTMS CHECKLISTDid the contractor assign lane numbers inside the cabinet to piezos/loops? ______Is cabinet level? ______Is cabinet accessible? ______Is the dirt and grass replaced? ______Is dirt compacted to avoid erosion issues? ______Are all dust, residue and compounds out of the roadway? ______
88 PTMS CHECKLISTIs cabinet and grounding according to specifications? ______Is conduit being used approved? ______Are all schematic, paperwork, and warranty cards placed in cabinet? ______Does cabinet lock and secure properly? ___