Targeted Overlay Pavement Solutions (TOPS)

What is Targeted Overlay Pavement Solutions (TOPS)?

Solutions for integrating innovative overlay procedures into practices that can improve performance, lessen traffic impacts, and reduce the cost of pavement ownership.

Approximately half of all infrastructure dollars are invested in pavements, and more than half of that investment is in overlays. By enhancing overlay performance, state and local highway agencies can maximize this investment and help ensure safer, longer-lasting roadways for the traveling public.

Improved Pavements that Last Longer

Many of the pavements in the nation's highway system have reached or are approaching the end of their design life. These roadways still carry daily traffic that often far exceeds their initial design criteria. Overlays are now available for both asphalt and concrete pavements that enable agencies to provide long-life performance under a wide range of traffic, environmental, and existing pavement conditions.

Concrete overlays now benefit from performance-engineered mixtures, including thinner-bonded and unbonded overlays with fiber reinforcement, interlayer materials, and new design procedures that improve durability and performance. Asphalt overlay mixtures have also advanced significantly with the use of stone-matrix asphalt (SMA), polymer-modified asphalt (PMA), and other materials and agents that reduce rutting, increase cracking resistance, and extend pavement life.


Safety. Thousands of miles of rural and urban pavements need structural enhancement and improved surface characteristics, such as smoothness, friction, and noise. Targeted overlay pavement solutions can improve the condition of highways significantly in a relatively short time.

Cost Savings. Timely and well-designed overlay applications are consistently cost-effective because less subsurface work is required. In urban areas, impacts to utilities and pedestrian facilities are minimized.

Performance. Targeting overlay solutions to high-maintenance areas such as intersections, bus lanes, ramps, and curved alignments can pay immediate dividends in terms of reduced maintenance needs, fewer work zones, and improved safety.

Learn more about this EDC-6 Innovation.


Stage of Innovation:
(December 2022)

New Jersey has been a leader in Targeted Overlay Pavement Solutions (TOPS). The following activities occurred in under previous EDC rounds:

High-Performance Thin Overlay (HPTO). NJDOT incorporated HPTO into its standard specifications and has used it for the preservation of good pavement and as the surface course on some composite pavement overlays. HPTO is also used by the Structural Design unit for bridge deck overlay.

Crack Attenuating Mixture. NJDOT incorporated this into its standard specifications and has used it for the intermediate course on some composite pavement overlays followed by SMA surface course.

Stone Matrix Asphalt (SMA). NJDOT incorporated SMA into standard specifications and has used it for the surface course on high traffic pavement, for the surface course on some composite pavement overlays, and over top of BRIC mix as overlay of composite pavements.

Asphalt Rubber Gap-Graded (ARGG). NJDOT incorporated ARGG into its standard specifications and has used it for the surface and/or intermediate course on some composite pavement overlays.

Open-Graded Friction Course (OGFC). NJDOT incorporated OGFC into its standard specifications and has used it for full depth porous asphalt pavements in outside shoulders, parking lots, pathways, sidewalks and other low traffic pavements.

Ultra-Thin Bonded Wearing Course (UTBWC) / Ultra-Thin Friction Course (UTFC). NJDOT incorporated UTFC into its standard specifications and used it for preservation of good pavement and for the surface course on some resurfacing pavement overlays.

What’s Next?

The Rt.42 Pavement Preservation project, using Ultra-HPTO / Highly Modified Asphalt (HiMA), is in construction. The Department plans to monitor closely and analyze the pros and cons of utilizing this type of asphalt mixture on NJ concrete pavements.

NJDOT Pavement Management unit procured new skid testing equipment in 2022. Skid testing was done for 9 projects by NJDOT Pavement Management unit on High Friction Surface Treatment (HFST)sections. Skid testing by the NJDOT Pavement Management unit on high friction surface treatment sections and alternative enhanced friction overlay (EFO) sections will continue using the new equipment.  There are plans to test, analyze, and monitor skid test results to advise the department on future development and use of enhanced friction overlay treatments. The Department is also working with an academic partner to perform companion testing of these friction test sections with a Dynamic Friction Tester (DFT) unit.

Ultra High Performance Thin Overlay is included in one project (UPC 213090). Specification is finalized and the item number has been created.

Compilation and analysis of all data on the different Enhanced Friction overlay surfaces, will lead to better information for NJDOT staff and others on the recommended use and practices with EFOs. Skid test equipment function and calibration are critical to collecting and analyzing the data. Other test methods will be explored.

Targeted Overlay Pavement Solutions (TOPS): NEW & NOTEWORTHY 

Targeted Overlay Payment Solutions (TOPS): NJDOT Example Featured

Targeted Overlay Payment Solutions (TOPS): NJDOT Example Featured

The FHWA's EDC News Weekly Newsletter featured NJDOT's use of HPTO as a cost-effective pavement preservation tool. ...
Lunchtime Tech Talk! WEBINAR: NJDOT’s Pavement Support Program—Goals, Deliverables and the Future

Lunchtime Tech Talk! WEBINAR: NJDOT’s Pavement Support Program—Goals, Deliverables and the Future

Dr. Thomas Bennert, who leads the Pavement Support Program (PSP), discussed how the group's research supports NJDOT's efforts to improve pavements across the state. ...
Pavement Preservation Treatments at NJDOT

Pavement Preservation Treatments at NJDOT

This video features the work that the NJDOT Pavement and Drainage Management and Technology Unit is doing to advance Pavement Preservation treatments on state roads to increase ...
Paving the Way to Better Roads at Lower Costs

Paving the Way to Better Roads at Lower Costs

Pavement preservation is just one example among many of how NJDOT is committed to keeping New Jersey’s roadways in a state of good repair and ...
Quantifying Greenhouse Gas Emissions of Asphalt Pavement Preservation at Construction and Use Stages Using Life Cycle Assessment

Quantifying Greenhouse Gas Emissions of Asphalt Pavement Preservation at Construction and Use Stages Using Life Cycle Assessment

A recent study found that pavement preservation techniques can reduce greenhouse gas emissions and contribute to savings for both transportation agencies and drivers. ...

Targeted Overlay Payment Solutions (TOPS): NJDOT Example Featured

This article first appeared in the FHWA’s EDC News Weekly Newsletter of August 26th, 2021 and featured NJDOT’s application of high performance thin overlays (HPTO) as a pavement preservation tool.

Targeted Overlay Pavement Solutions

Last week, we discussed a case study involving bonded concrete overlays, part of the Targeted Overlay Pavement Solutions (TOPS) toolbox. This week, we’ll look at how New Jersey has used high performance thin overlays (HPTO) successfully as a pavement preservation tool.

Since 2015, NJDOT has used HPTO on more than 1,000 lane miles to seal pavement and improve ride quality. Benefits include short road closures reducing impact on traffic, and addition of approximately 10 years of service life. Timing of the application is crucial. A Rutgers University study found applying HPTO to pavements while they are still in “good” condition more than doubles the service life compared to applying the product to pavements in “fair” condition.

Contractors who construct NJDOT projects have not reported constructability issues or complaints about the mix. NJDOT believes including performance requirements for the mixture, understanding treatment selection and application timing, and requiring project engineers to approve specifications are key factors in the success of HPTO as a pavement preservation tool.

Based on this research and evaluation of projects to date, NJDOT considers HPTO a cost-effective solution that provides a safe, smooth, crack and rut resistant surface that extends the life of the pavement and causes minimal impact on the road users and environment during construction.

Reads: Lunchtime Tech Talk! The NJDOT's Pavement Support Program (PSP), Goals, Deliverables, and the Future, Thursday July 22, 2021, 12pm to 1:15pm

Lunchtime Tech Talk! WEBINAR: NJDOT’s Pavement Support Program—Goals, Deliverables and the Future

Dr. Thomas Bennert, of the Center for Advanced Infrastructure (CAIT) at Rutgers University, presented on Thursday, July 22, on his work leading the Pavement Support Program (PSP) for NJDOT’s Pavement & Drainage Management and Technology Unit. Dr. Bennert discussed in detail PSP’s current research and applications, explaining how a variety of innovative materials and technologies are being developed and applied to improve pavement performance across the state.

Dr. Bennert's talk provided an overview of the pavement program’s recent deliverables, as well as highlighted the future goals of the program. The PSP has several objectives and touches upon many disciplines from materials evaluation to supporting pavement management activities to addressing pavement design needs to assisting in training and workforce development. The PSP serves as an extension of the NJDOT workforce activities under the direction of the Pavement & Drainage Management and Technology Unit at NJDOT, which also helps to support the needs of the NJDOT Materials Bureau to inform materials characterization for more accurate pavement design and evaluation.

Since 2006, the PSP has assisted NJDOT through research and technical assistance related to pavement performance. Because of this continual, fifteen-year operation, data is available today that demonstrates the positive effects of the program’s work, such as how various asphalt composites have performed over time in comparison to traditional asphalt mixes.

Slide reading NJDOT Pavement System, how it's going. A bar graph of deficient, fair, and good pavement statuses, with deficient tending down since 2006, and good trending upwards.

Data indicates a steady upward trend in the condition of New Jersey’s highway pavement, due to the sustained implementation of PSP’s research and deployment of various pavement preservation treatments

Dr. Bennert organized his talk by the seven major support tasks of the PSP, highlighting the purpose, examples and upcoming activities for each task. For the program’s first task, Innovative Materials, the program has focused on the development and improvement of specifications for roadway pavements, such as asphalt and concrete, to extend the life of the pavement. High Performance Thin Overlay (HPTO) was one of several examples whose purpose, design attributes and benefits were discussed. This pavement treatment improves rut and crack resistance, and extends the life expectancy of some pavements by over five years.

Dr. Bennert also touched on the rationale and challenges of applying another materials innovation, High Friction Surface Treatment (HFST), which was promoted as an FHWA Every Day Counts (EDC) initiative in 2015. While horizontal curves make up only 5 percent of U.S. roadways, more than 25 percent of total roadway fatalities occur on these sections. One way to increase friction in these areas is to apply an HFST, though the pavement must be in good condition. In New Jersey, rapid temperature swings can affect the epoxy on degraded asphalt, creating shallow potholes. To counter this failure, Dr. Bennert and his team have developed both a pre-screening protocol to determine whether a curve is suited for HFST, and a different adhesive more suited to asphalt.

Slide reads Task 2 - Pavement Bonding (Tack Coats & Bond Strength Test), with immages of defromed pavement. A graphic shows how tension between two layers of pavement that are not properly bonded creates space for friction. Bullet points read: Pavement construction requires construction layers in "lifts." Pavement design is conducted assuming layers are "fully bonded," Poor bonding in HMA layer is associated with, reduced fatigue life, increased drutting, and slippage, cracking, and instability.

The program team developed ways to improve pavement bonding in roadway construction

PSP is also tasked with researching innovative practices and technologies to improve the efficacy of the paving process. One example that Dr. Bennert shared involved researching ways to improve the pavement bonding. Two common problems are slippage, where the top layer does not adhere properly and begins to slide away, and more widespread tension issues, in which failure to bond causes uneven loads, warping the pavement. To avoid premature failure, the program has developed performance-based specifications for tack coats (the term for the adhesive layer between tiers of asphalt), a testing mechanism to better understand the properties of tack coats, and new criteria for construction practices to ensure that pavement is put together properly.

The PSP includes a pavement management system support task to assist NJDOT in the collection of data, the management and quality control of data, and the application of data to inform decision-making priorities. For example, the NJDOT Pavement Management group conducts yearly pavement condition assessments to help forecast needs of pavement activities and funding allocations to optimize budgetary resources for pavement preservation and larger rehabilitation and reconstruction projects. This process uses Pavement Management Systems (PMS) condition and program mapping, and future work is expected to continue to incorporate GIS mapping models to create an even more comprehensive picture.

Until recently, the status of the state’s many miles of pavement has been historically performed using an employee’s vision and judgment. Instead, PSP is looking to deploy cameras and computer-based processing power along roadways to automate data collection for developing surface distress index ratings, and even to calibrate and predict the infrastructure’s future performance to inform Pavement Design.

Slide is a map of New Jersey with colored lines across its roads, reflecting pavement conditions. Text to the left reads Developing Visual Tools that NJDOT PMS can utilize for programming and reporting, Construction programming, Planning, Pavement Preservation, and Rehab and Reconstruction

New methods in data collection and mapping allow for a more comprehensive picture of pavement conditions across the state

Finally, PSP engages in policy analysis, develops white papers on current and emerging practices, and provides technology transfer and trainings for NJDOT. Such work includes Cost Benefit Analyses (CBAs) to determine the cost effectiveness of new materials, tackling the question of whether the additional costs to manufacture can be justified by the additional years added to the roadway’s life cycle. Dr. Bennert shared slides showing how CBAs of HPTO and several other hybrid asphalt mixes had higher Benefit/Cost Ratios than traditional Hot Mix Asphalt (HMA). The program engages in trainings and presentations with NJDOT regularly, presenting on research and technological innovations, and facilitating technology transfer and continuity for newer staff.

Dr. Bennert concluded his presentation by commending NJDOT as a national leader in performance testing for asphalt and handling of composite pavements. The Pavement Support Program will continue to address the immediate needs of the Pavement & Drainage Management and Technology Unit at NJDOT, sustaining their research, development, and implementation of cutting-edge pavement technologies. “What we’re doing here is making a big impact in the state.” Dr. Bennert said.

Afterward, Dr. Bennert answered audience questions in a brief Q&A.

Q. How does New Jersey compare to other states in our use of high performance thin overlay (HPTO)?
Dr. Bennert: We’re working with FHWA on the EDC-6 rollout of HPTO. We use it significantly more than most states, besides Texas. New Jersey is a leader on performance testing in general.

Q. How widespread is the use of the High Friction Surface Treatment (HFST) in New Jersey?
Dr. Bennert: While I don’t have the crash reduction data, I do know that it’s been used successfully by the state and some municipalities as well. As shown earlier, there have been some failures with the technology’s application, which we are now working to identify the reasons for failure and reduce through our research.

Q. As reported in the HFST guidelines, why do you think an early drop in skid resistance was observed in the treatment’s application, despite the very hard aggregate that was used?
Dr. Bennert: Simply, it is due to the material loosening in the epoxy. The embedment depth of that aggregate is very important. If it’s too deep, the aggregate is almost drowning in the epoxy, and if it too shallow, it can pull out very easily as vehicles travel over it. The recommendation is to monitor the HFST over the first few years. Because HFST has a limited shelf-life, monitoring friction is very important.

Q. How many sub-consultants do you have on this project, and which private consultants are contracted as sub-consultants?
Dr. Bennert: Currently, the only group that we have working with us on the contract this year is the company that manufactures the software for the pavement management system. This can change based on the needs of Pavement & Drainage Management and Technology Unit at NJDOT.

Q. Could you speak on pavement mix testing for future climate concerns?
Dr. Bennert: We have tests and thresholds for how the material should be performing, and additional heat will often stiffen the material a bit more, which can further age the pavement. We could get some increased, accelerated stiffening. PSP has been working with NJDOT on test methods to identify appropriate asphalt materials and test methods to help identify materials that are prone to aging, which could be especially useful to address climate concerns.

Q. What is the future of Cold Mix Asphalt and its potential use on heavily truck trafficked New Jersey highways?
Dr. Bennert: In New Jersey, we don’t have low volume roads where we could put material out without an overlay. Without some kind of confinement, the material could easily break apart. I’m looking forward to the rollout of central plant technology, which will allow us to take material from a project and put that back, an almost 100 percent recycling of the material for a project’s base application. This would be a base application to help reduce the recycled asphalt pavement stockpiles in the state.

Q. Did you test Ultra-Thin Friction Course and how does it compare to High Performance Thin Overlay?
Dr. Bennert: Ultra-Thin Friction Course can be thought of as a treatment option between an Open-Graded Friction Course and a Chip Seal. It’s used more for pavement preservation, rather than structure, but it does a good job at sealing off the pavement. The High Performance Thin Overlay is thicker, and helps to provide structural integrity of the pavement, both sealing it and adding rutting and cracking resistance. There’s a difference in the thickness of the materials, and the targeted applications.


A recording of the webinar is available here, (or to the right).

Dr. Bennert’s presentation can be found here.


Federal Highway Administration. Targeted Overlay Pavement Solutions.

Bennert T. and D. Pezeshki. (2015). Performance Testing for HMA Quality Assurance. Report, Rutgers, Center for Advanced Infrastructure and Technology. FHWA-NJ-2015-010.

NJDOT Technology Transfer. Pavement Preservation at NJDOT. Video.

Pavement Preservation Treatments at NJDOT

NJDOT's Pavement and Drainage Management and Technology Unit is advancing the use of Pavement Preservation treatments on the state's roads to increase safety, enhance durability, improve customer experience and minimize costs. Pavement rehabilitation is needed for deficient roadways, but pavement preservation can extend pavement life for state highways in good and fair condition. 

Watch this educational video to learn more about the Pavement Preservation program at NJDOT and the tools in the pavement preservation toolbox. The video explains the rationale for maintaining roads in a state of good repair and establishing a dedicated program for pavement preservation. The video highlights several pavement preservation treatments in the NJDOT toolbox and how, when and why the treatments are used.

Paving the Way to Better Roads at Lower Costs

Pavement Preservation Projects Benefit New Jersey Taxpayers and Commuters

Diane Gutierrez-Scaccetti, Commission of the NJ Department of Transportation

The last Commitment to Communities newsletter (Volume 7) highlighted some of the wonderful volunteerism of New Jersey Department of Transportation (NJDOT) employees. In this volume, I will share how the NJDOT achieves consistent progress through focused investments that keep our infrastructure in a state of good repair. Not only does the NJDOT prioritize improving the quality of life for our residents, but we also take great pride in the preservation and maintenance of our transportation system for the benefit of all New Jerseyans.

Within the last decade, NJDOT has significantly increased our use of pavement preservation treatments and preventive maintenance. Instead of waiting until pavements deteriorate to poor conditions requiring conventional, more costly resurfacing or rehabilitation treatments, preventive maintenance treatments are being applied at a fraction of the cost to sections of roadway in good or fair condition.

Slurry Seal treatment being applied to the Route 33, CR 527 to Howell Road Pavement Preservation Project in Monmouth County.

The purpose of these treatments is to renew and seal the pavement surface and extend the functional life of the pavement by six to twelve years depending on the preservation method. Sealing the roadway prior to deterioration reduces the chances for water to infiltrate the pavement and therefore prevents the opportunity for potholes to form. Since preservation treatments are less expensive than traditional resurfacing (one third to one half of the cost) preservation becomes a more cost effective life cycle treatment strategy while also minimizing the opportunity for potholes to develop throughout the life of the pavement.

In addition to providing cost savings to the state (and in turn, the tax payer), these methods can be implemented without major traffic disruptions and with minimal lane closures—saving commuters time and frustration. Furthermore, these projects have an accelerated design and construction phase, with most projects completed in one year.

Completed Route 33, CR 527 to Howell Road Pavement Preservation Project in Monmouth County.

The method of pavement preservation is not an idea unique to NJDOT. This method is nationally accepted as a cost effective treatment in pavement life cycle strategy. As a Department, we participate in the North East Pavement Preservation Partnership (NEPPP), a regional component of the national pavement preservation initiative facilitated by the National Center for Pavement Preservation.

System preservation is a requirement under federal legislation MAP-21, the Moving Ahead for Progress in the 21st Century Act. MAP-21 offers much needed funds in transportation investment.

Because these preventive techniques are so beneficial, we have substantially increased our annual investment in pavement preservation projects from $3 million in 2013 to $50 million in the 2020 program. Over the last two years, we have successfully designed or delivered 22 projects. They reflect our commitment to be responsible stewards of the 27-cent gas tax increase.

We look forward to increasing our investment levels in future years.

Pavement preservation is just one example among many of how NJDOT is committed to keeping New Jersey’s roadways in a state of good repair and by doing so, improving the lives of our residents. I strongly believe that any opportunity where we can take a proactive approach and in turn save the state and taxpayer time, money and disruption is an opportunity worth investing in.

Once again, thank you for taking the time to read this and please feel free to share it with your colleagues. If you have any questions about any of the information in the newsletter, please feel free to contact NJDOT’s Office of Constituent Relations at 609-963-1982.

Diane Gutierrez-Scaccetti

This article first appeared in the Fall 2019 NJDOT Commitment to Communities Newsletter.

Quantifying Greenhouse Gas Emissions of Asphalt Pavement Preservation at Construction and Use Stages Using Life Cycle Assessment

Employing pavement preservation techniques can help reduce greenhouse gas emissions, and contribute to savings for both transportation agencies and drivers, according to a recently published study in the International Journal of Sustainable Transportation. The researchers determined that extending the life of pavement through preventive maintenance  can reduce greenhouse gases by 2 percent; save transportation agencies between 10 to 30 percent in spending; and reduce cost for drivers between 2 to 5 percent on fuel consumption, tire wear, vehicle repair, and maintenance because of smoother surfaces (Bates 2019). This research can assist transportation agencies like NJDOT and local public agencies consider the right maintenance strategies when determining environmental effects in future projects.

This research is notable, in part, because pavement preservation has been a hot topic among many state highway agencies.  The Federal Highway Administration’s Every Day Counts (EDC) program brought greater attention to the benefits of pavement preservation by making it one of its national initiatives in the fourth round of the EDC program. Through EDC-4, many states made commitments to increase their use of pavement preservation treatments and give a fuller commitment to its integration in their maintenance programs (FHWA 2018a).

NJDOT has significantly increased its use of preventive maintenance treatments on roadways in good or fair condition in recent years. Applying preventive maintenance treatments early has proven to be cost-effective by slowing the rate of deterioration and allowing NJDOT to reduce the backlog of deficient pavements.  The lead author  for this research, Hao Wang, previously worked as the co-investigator on a NJDOT-funded research study, Appropriate Implementation of Pavement Preservation Treatments, completed in 2015. That study looked at the pavement preservation techniques that NJDOT could use on its high volume state-maintained roads (Wang & Vitillo 2015).

Pavement preservation consists of surface refreshment to alleviate functional indicators of deterioration, such as friction, minor cracking, or oxidation. The three pavement preservation treatments considered in this recently published research were thin asphalt overlay (placing up to 2 inches of asphalt on roads), chip seal (spraying asphalt emulsion on pavement and laying aggregate), and crack seal (filling cracks with rubberized asphalt or polymer-modified asphalt with some filler).

While previous studies have looked at the environmental impact of preservation treatments at the construction stage, few have considered how the change in pavement smoothness affects vehicle fuel consumption and tailpipe emissions. The purpose of this study was therefore to systematically look at both the construction and use stage to determine the environmental impacts of several pavement preservation treatments throughout the whole life-cycle.

In order to quantify the environmental impact, the researchers used life-cycle assessment (LCA), focusing specifically on CO2 emission for global warming potential (GWP). To determine the emissions during construction stage, the group looked at the raw material, manufacturing, transport, and placement.

Illustration of different stages in pavement LCA with system boundary (Wang et  al. 2019)

Researchers measured pavement condition using the International Roughness Index (IRI), which states are required to report to the FHWA as it provides a standardized and objective measurement methodology. IRI models for pre- and post-treatment were then created with data obtained from the Long-Term Pavement Performance (LTTP) program Specific Pavement Studies (SPS-3). The LTTP program was established in 1986, and has been maintained by the FHWA since 1991, with the purpose of collecting and storing pavement performance data in a centralized database (FHWA 2019). SPS-3: Preventive Maintenance Effectiveness of Flexible Pavements specifically compares the effectiveness and mechanisms of selected maintenance treatments to preserve and extend pavement service life, safety, and ride quality (FHWA 2018).

The pavement’s pre- and post-treatment effects on vehicle fuel consumption and air quality were then analyzed using data from the Highway Development and Management Tool (HDM-4) and the Motor Vehicle Emission Simulator (MOVES). HDM-4 is a software package that is used worldwide for analysis, planning, management, and appraisal of road maintenance, improvements, and investment decisions. MOVES is the EPA’s emission modeling system for mobile sources, which is used at all project levels to estimate for criteria air pollutants, greenhouse gases, and air toxics.

The results for the CO2 emissions at the construction stage showed significant differences in energy consumption for the three pavement preservation treatments, mostly due to the varying raw materials and manufacturing processes. Thin asphalt overlay had the highest energy consumption, followed by chip seal, and then crack seal, which requires a comparatively small amount of material over the entire process. Additionally, thin asphalt overlay tends to have a higher cost compared to the other two. At the use stage though, thin overlay showed the highest reduction of CO2 emissions, based on the post-treatment IRI values, and crack seal the lowest reduction.

A machine compacts asphalt over existing pavement at a construction site at John F. Kennedy International Airport in New York City (Wang 2019).

Despite their environmental impacts, the various preservation treatments still had an overall benefit when quantified using a life-cycle assessment approach, according to the researchers. Additionally, they found that the timing of preservation treatment could have a large effect on the subsequent emissions at the use stage. Specifically, for thin overlay and chip seal, the optimal time to achieve maximum life-cycle environmental benefit becomes earlier as traffic volume or initial IRI value increases. Despite the variance in effectiveness over the life-cycle, all three treatments reduced emissions overall.

In explaining the rationale for the research, the study’s authors  note that transportation sector is second to electricity in generating greenhouse gas emissions among all U.S. end-use sectors at 27 percent. Additionally, fuel consumption of vehicles accounted for 83 percent of the total greenhouse gas emissions within the transportation sector in 2015. In December 2018, Governor Phil Murphy announced that New Jersey would be rejoining the Regional Greenhouse Gas Initiative, a group of neighboring states that have set policy goals and initiatives in order to achieve a 100-percent clean-energy portfolio by 2050 (Murphy 2018). Improving the performance of existing highways is well-aligned with this initiative.

By filling the gap in research focused on  the entire life-cycle environmental impacts of pavement preservation treatments, the research offers important information for life-cycle assessment in future roadway projects. As transportation agencies look at how to manage their current assets, reduce costs, and avoid and minimize environmental impacts, pavement preservation offers a multitude of benefits to help achieve these goals.

Shown above is a Bergkamp M1, which can be used for slurry seal and microsurfacing. Source: By Eric Pulley – Own work, CC BY-SA 3.0,


Bates, Todd. “Keeping Roads in Good Shape Reduces Greenhouse Gas Emissions, Rutgers-Led Study Finds.” Rutgers Today. January 14, 2019.

BTS. “Road Condition.” Bureau of Transportation Statistics. June 2015.

FHWA. “Long-Term Pavement Performance.” FHWA. 2019.

FHWA. “Pavement Preservation (When, Where, and How).” Center for Accelerating Innovation. May 30, 2018a.

FHWA. “Specific Pavement Studies.” FHWA. March 12, 2018b.

Murphy, Phil. “Murphy Administration Proposes Rules For State’s Re-Entry Into Regional Greenhouse Gas Initiative.” Office of the Governor. December 17, 2018.

Vitillo, Nicholas, and Hao Wang. “Appropriate Implementation of Pavement Preservation Treatments.” NJDOT. April 2015.

Wang, Hao, Israa Al-Saadi, Pan Lu, and Abbas Jasim. “Quantifying Greenhouse Gas Emission of Asphalt Pavement Preservation at Construction and Use Stages Using Life-cycle Assessment.” International Journal of Sustainable Transportation. January 11, 2019.