City of Houston Street Surface Assessment Vehicle Presented to the Flooding & Drainage Committee Eric K. Dargan – Deputy Director
Pavement Assessments for Roadways in the City of Houston Pavement Condition Rating (PCR) Usage of PCR scores 1999-2001 IMMP (Infrastructure Maintenance Management Program) In order to assess the condition of a roadway section, various pieces of data are gathered to generate one overall PCR (Pavement Condition Rating) score for the specified area. The goal of this data collection is to provide a clear understanding of where the City is concerning the condition of its streets and take that data to guide maintenance/project decisions. The City previously conducted a pavement assessment from 1999-2001 through the IMMP (Infrastructure Maintenance Management Program).
Typical Roadway Problems RUTTING ALLIGATOR CRACKING RAVELLING TRANSVERSE CRACKING
Typical Roadway Problems LONGITUDINAL CRACKING CONCRETE CRACKS JOINT SEAL SLAB REPLACEMENT
IMMP IMMP program – Evaluated by individuals IMMP PCR Score Factors: Rutting Raveling Alligator Cracking Transverse Cracking Longitudinal Cracking Joint Seal Present Patching Flushing Surface Deterioration Faulting Slab cracking* Slab Replacements* Ride Condition (*concrete only) The IMMP program relied heavily on human judgment for a PCR creation. A PCR score was generated by quantifying cracking and assessing the overall ride condition by a specific person. To assess the road surface, an individual would travel the street and photograph it. Timeliness, score consistency and safety were concerns. The range identified in the IMMP data varied depending on the evaluator. Actual scores ranged from 0 – 100. If any of these above were present then to what degree had to be determined, Slight, Moderate, and Extreme were the parameters to input into each of these above if there was any present. A score was generated off of this data entry. For example, if none of the above criteria was found at a street, NA was put into all the blanks and a 100 score was achieved. A very low score was generated if extreme was inputted for every piece of criteria.
Overview of the Street Surface Assessment Vehicle (SSAV) Procured from Idea Integration, Inc. in August 2008 Data testing began July 2009 Full production began May 2010 Assessments are anticipated to occur every 2-3 years Estimated 5-year system life = 3 Assessments The Street Surface Assessment Vehicle (SSAV) was acquired by the City from Idea Integration, Inc. in August 2008 for $1.2 million to collect data, images and video of the pavement in the area where it is traveling. The operation of this vehicle requires a minimum of two persons, one to drive and one to operate and monitor the computer systems collecting the data. Typically, three people are in the van to rotate duties and to assist with data collection and navigation. There is also on project coordinator and one data processor separate from the field ops. The data collected was originally designed to guide maintenance decisions regarding the roadways of the City as well as for federal reporting requirements (GASB 34 fixed asset reporting/depreciation) How much does the total assessment cost???
Assessment Costs Contract rate per assessment - $1.7M (no video) PWE Annual Total Operational Cost - $590k (includes video collection) 3 Assessments over 5 years = $5.21M contract cost vs. $2.95M internal costs Possible future partnerships with other area agencies may recoup some costs The Street Surface Assessment Vehicle (SSAV) was acquired by the City from Idea Integration, Inc. in August 2008 for $1.2 million to collect data, images and video of the pavement in the area where it is traveling. The operation of this vehicle requires a minimum of two persons, one to drive and one to operate and monitor the computer systems collecting the data. Typically, three people are in the van to rotate duties and to assist with data collection and navigation. There is also on project coordinator and one data processor separate from the field ops. The data collected was originally designed to guide maintenance decisions regarding the roadways of the City as well as for federal reporting requirements (GASB 34 fixed asset reporting/depreciation) How much does the total assessment cost???
Technical Components of the Street Surface Assessment Vehicle CrackScope 360 degree camera GPS Unit The following systems are onboard the vehicle: Road Profiler: The Road Profiler is mounted on the front bumper of the vehicle. It contains three lasers and two accelerometers that are used to capture both the roughness (IRI) and the rutting of the road. Line Scan Camera System(CrackScope): The vehicle is outfitted above the back end with a line-scan camera system called CrackScope. It takes high-resolution images that are analyzed by post processing software to automatically detect the severity & extent of cracking on the pavement. 360° Video: A camera ball with 11 cameras taking 30 frames per second is mounted on a mechanical arm that extends above the van. The video produced allows the user to pan in all directions while viewing the right-of-way. This is similar to the Google Street View technology. GPS and DMI Devices: The vehicle is also equipped with a Trimble GPS receiver and a DMI (Distance Measurement Instrument) device. The data from these instruments is used in post processing to tie components together and calculate the position of the vehicle. Distance Measuring Instrument Road Profiler
SSAV Capabilities Assesses asphalt/concrete roads in clear weather Measures distance traveled only (center-line miles) Does not currently identify or “asset tag” any items Program relies on machines and specific software to create a more consistent PCR score For a road section, 100 is the starting value. Three reductions bring the PCR to its final number. IRI or ‘roughness’ deduction Rutting deduction Cracking deduction The SSAV program relies on machines and specific software to create a PCR score. A score is generated by driving the vehicle over a specified area of street. The instruments on the van assess the road surface condition and generates a score. This provides for a safer and more consistent means of calculating a PCR score. In looking at the data so far, scores have ranged from 38 to 100. What is IRI? International Roughness Index – The standard road roughness index for evaluating street conditions Potholes do not have any effect on the PCR score; the number is gathered manually by field personnel.
What Happens Next? Upcoming Completion Schedule 11/30/2010 – 56% 12/31/2010 – 62% 03/30/2011 – 82% 06/30/2011 – 100% Video capture is being used for identification of key items Actual completion time depends on the ability for the van to be on the road By Dec. 31, 2010, we are currently tracking to be 62% complete with all COH roads. On March 30, 2011, we are estimating to be 82% complete with all COH roads. On June 30, 2011, we believe we will be 100% complete with the City roadway system. Completion of an area includes the PCR score, as well as manually identifying whether the street is curb and gutter or open ditch, and if a sidewalk is present at the location. The decision to track that data was made midway through the production process. As a result, video is being used for those areas prior to the decision being made. Field observations are ongoing for areas that have been done since the decision. There is currently no automated feature to collect this data. Actual completion time depends on the ability for the van to be on the road. Unforeseen delays such as vehicle trouble, loss of work days, staffing issues, weather, or other technical issues could delay the schedule as outlined.
How Will We Use This Data? To guide and expand maintenance programs Overlay program Concrete repairs Primary factor for development and scheduling capital projects for streets The PCR score is not the only factor that will drive project selection. Other factors affecting the prioritization of future projects will include partnership funding, land acquisition issues, mobility/transportation issues, emergency response concerns, other infrastructure needs in the area, as well as other factors yet to be determined. These future capital projects identified may be funded via the Street & Drainage Fund. This fund will include fees collected as a result of the Renew Houston initiative that passed in November 2010. Projects utilizing those dedicated funds would not begin until the program builds up an adequate fund balance. As a result, it is estimated that projects funded through those fees would not begin until FY2016.
Council Districts & SSAV Data TOTAL SSAV MILES COMPLETE A 413 B 533 C 178 D 346 E 724 F 52 G 208 H 656 I 471
20 Worst Scored Thoroughfare Street Sections in the City Key Map Council District Street Name From Block To Block Potholes Observed Overall PCR Score Miles Driven 492M G SHEPHERD DR 300 1399 52 50.607 0.503 453P, T, X H AIRLINE DR 1700 2999 76 50.63 1.821 535F, K I BROADWAY ST 1900 2699 31 50.71 1.044 494N SAMPSON ST 100 1099 37 52.06 0.606 493L PRAIRIE ST 700 1299 4 53.26 0.27 N SAMPSON ST 1 299 22 53.46 0.278 576K,L,P E S SHAVER ST 4900 4905 27 54.07 1.062 493V, U DOWLING ST 1950 2599 49 54.2 0.61 452X A ELLA BLVD 1999 16 54.26 0.317 493H, 494H B LORRAINE ST 2000 2849 15 54.41 0.349 494C, D B, H WALLISVILLE RD 5600 6499 70 54.58 1.225 533D D CULLEN BLVD 3534 3899 56 54.82 0.63 492Y S SHEPHERD DR 3600 3999 5 55.12 0.28 532K, P C BUFFALO SPDWY 7900 9499 29 55.13 1.767 532K,L,N,P S BRAESWOOD BLVD 2490 4199 144 55.2 3.424 493T, X D, I ALABAMA ST 900 1499 55.59 0.803 534L S WAYSIDE DR 3800 4999 55.76 0.55 493J W DALLAS ST 2400 2909 6 55.98 0.258 616B HUGHES RD 10418 11175 11 1.391 453Z, 454W COLLINGSWORTH ST 2799 18 56.86 0.048 The data collected is kept in a database so that overall street conditions can be viewed and compared citywide. Data is added daily when the van is operating. Published results of the data are updated in several formats monthly. This allows for the public to view data that is up to date and accurate.
Questions?