When aging highway surfaces begin to lose their skid resistance, transportation agencies must choose cost-effective solutions that extend pavement life without breaking the budget. Micro surfacing has emerged as a proven pavement preservation technique that delivers durable, high-friction surfaces at a fraction of the cost of full-depth overlays. This article examines how Micro-Surfacing Inc. (MSI) successfully executed one of the largest interstate micro surfacing projects ever undertaken in the four-state region of Missouri, Illinois, Indiana, and Iowa. Understanding the scope and coordination required for such a project helps contractors appreciate the importance of Key Facts About Construction Project Life Cycle Phases when planning large-scale pavement preservation work.
Understanding Micro Surfacing as a Pavement Preservation Strategy
What Is Micro Surfacing?
Micro surfacing is a polymer-modified, cold-mixed, quick-setting asphalt resurfacing material designed to remedy a broad range of problems on today’s highways. It is applied in a semi-liquid condition using specialized mixing and paving equipment. Once placed, the material chemically changes from a semi-liquid into a dense cold mix that can carry normal traffic within one hour after application. This rapid cure time makes micro surfacing ideal for high-traffic urban interstates where minimizing lane closure duration is critical.
Key Benefits Over Traditional Overlays
A full-depth hot mix asphalt overlay costs significantly more than micro surfacing while delivering similar surface performance for skid resistance and waterproofing. The MSI project on I-70 and I-270 demonstrated this value proposition clearly: many motorists and MoDOT employees believed the micro surfaced roadway had been overlaid, which is a much more costly application. The key advantages of micro surfacing include:
- Cost efficiency — Lower material and placement costs compared to hot mix overlays
- Rapid traffic return — Roads reopen within one hour of application
- Skid resistance improvement — Restores friction on polished surfaces
- Waterproofing — Seals the existing pavement from moisture infiltration
- Pavement life extension — Adds 5 to 7 years of service life to existing pavements
- Reduced environmental impact — Cold mix process consumes less energy than hot mix production
Situations Where Micro Surfacing Is the Right Choice
Micro surfacing works best on structurally sound pavements that have adequate load-bearing capacity but have lost surface friction due to traffic polishing. Common applications include:
- Interstate highways with polished aggregate surfaces
- Urban expressways with high traffic volumes (100,000 to 140,000 vehicles per day)
- Bridge decks requiring lightweight surface treatments
- Airport runways and taxiways needing friction restoration
- Parking lots and commercial pavement areas
The success of any micro surfacing project depends heavily on proper mix design, quality aggregate selection, and experienced application crews. The Construction Project Life Cycle Phases in Life Cycle of such a treatment require careful planning from material selection through final inspection.
Project Scope and Preparation on I-70 and I-270
Massive Scale and Multiple Pay Items
The I-70/I-270 micro surfacing project in St. Louis, Missouri was awarded in May 2011 and included 38 separate pay items. The scope extended well beyond simple surface treatment, encompassing milling, patching, hot mix asphalt concrete (HMAC) overlays, concrete patching, rumble strips, traffic control, and striping. The core micro surfacing work called for a two-pass, 30-pound total application of asphalt emulsion micro surfacing covering 746,937 square yards of roadway.
Preparation work alone required substantial resources:
- 11,000 tons of HMAC for ramp overlays and mainline patching
- Miscellaneous milling to level surface irregularities
- Cement repairs on deteriorated concrete sections
- Removal and replacement of existing pavement markings and inlaid markers
Materials and Equipment Used
For friction purposes, the project specification required air-cooled blast furnace slag aggregate, which provides excellent skid resistance due to its angular particle shape and hard wearing characteristics. The micro surfacing material was mixed and applied using a Bergkamp M-1 continuous paver, a specialized machine that proportionally blends aggregate, emulsified asphalt, water, and additives before delivering the mixture to a spreader box in a continuous operation.
The emulsion formulation was custom adjusted by the manufacturer, Bi-State Emulsion, to ensure proper mixing and setting behavior under the extreme summer temperatures encountered during the project. This mix design adjustment proved critical for achieving the one-hour cure time requirement.
Project Schedule and Deadlines
The project timeline was aggressive and carried significant financial penalties for delays.
| Milestone | Date | Details |
|---|---|---|
| Contract Award | May 2011 | Bidding and contract finalization |
| Patching Work Begins | June 23, 2011 | HMAC patching and concrete repairs |
| Micro Surfacing Begins | July 11, 2011 | Micro crew mobilization and production |
| Micro Surfacing Complete | September 15, 2011 | Target completion before Labor Day |
| HMA Work Complete | October 26, 2011 | Remaining HMAC overlay work finished |
| Final Deadline | November 1, 2011 | $21,625 per day penalty after this date |
The penalty structure created intense pressure to maintain the schedule. Additionally, night work restrictions imposed a $1,000 penalty for every 15-minute delay in reopening lanes by 5 a.m. each morning. Proper Construction Project Scheduling Methods Tools and Best Practices for On Time Project Delivery were essential to meeting these demanding deadlines.
Overcoming Night Work and Traffic Coordination Challenges
Strict Work Hour Restrictions
The project operated under a strict 8 p.m. to 5 a.m. work window, with all traffic control equipment and signage required to be off the roadway by 5 a.m. This meant crews had approximately eight hours each night to complete their work, allow for material cure time, and restripe the roadway before rush hour traffic began. Coordinating patching crews, micro surfacing crews, traffic control personnel, and striping crews within this tight window was the single biggest challenge of the project.
The striping operation was a critical path item. As Tom Ritschel, president of MSI, explained, the team knew exactly how much time was needed to put down new stripes, so all other work stopped to allow for striping, usually around 3 a.m. This hard cutoff ensured the roadway would be fully marked and safe for traffic by the 5 a.m. deadline.
Complex Ramp Management
Within the project limits there were 86 separate on-ramps and off-ramps. Consecutive ramps could not be closed at the same time, forcing the project team to sequence closures carefully to maintain access for emergency vehicles and local traffic. Project manager Dave Miller spent almost all of his time figuring out which crews could work where on any given night.
External Events and Unforeseen Disruptions
Several external events added complexity to the coordination effort:
- Cardinals night games — When the St. Louis Cardinals played at Busch Stadium, lane closure restrictions applied 45 minutes before and after each game, reducing available work time
- Presidential visit — A visit from President Barack Obama forced a full night of work cancellation with all signage removed for security reasons
- Extreme temperatures — Air temperatures reached 100 degrees Fahrenheit with pavement temperatures near 120 degrees Fahrenheit, requiring extra water supplies for the crew and adjustments to the emulsion chemistry
- Weather delays — Rain events pushed the micro surfacing completion slightly past the Labor Day target
Safety Performance
Despite the challenging conditions, the project achieved an outstanding safety record. Over more than 70 nights of work, with one or more crews operating simultaneously, there were zero accidents and zero work-related injuries. This safety performance reflects MSI’s experience working on high-traffic urban highways. The company had previously completed expressway night work in St. Louis, but never at this scale.
Quality Outcomes and Industry Recognition
On Time and Under Budget Delivery
With all its challenges, the I-70/I-270 project was completed on time and under budget. Dave Bauer, resident engineer with the Missouri Department of Transportation (MoDOT), praised the outcome: “I have received positive comments from both MoDOT employees as well as from the traveling public about the final appearance of the roadway. Many believed that the project overlaid the roadway, which is a much more costly application than micro surfacing.”
Bauer further noted, “In these hard economic times when money is in short supply to maintain our road and bridges, a quality micro surfacing application is a way to lengthen the life of our pavements in a cost-effective manner.” This sentiment underscores the value of pavement preservation techniques that stretch limited infrastructure budgets further without compromising quality.
Lessons for Future Projects
The MSI team’s approach to planning and execution offers valuable lessons for contractors tackling large-scale pavement preservation work:
- Start with a framework, then adjust daily — As Ritschel described, the team built a scheduling framework, added details as they went, observed how each night’s work progressed, and made adjustments every day based on real conditions
- Build contingency for external events — Sports schedules, presidential visits, and weather all required flexibility in the execution plan
- Coordinate striping as the critical path — Knowing the exact time needed for striping allowed other operations to plan their hard stop accordingly
- Adjust materials for site conditions — Working with the emulsion manufacturer to adjust the mix for extreme temperatures prevented cure-time failures
- Prioritize safety above all — Zero accidents on a 70-plus night project in high-traffic conditions demonstrates that rigorous safety protocols and experienced crews produce results
ISSA President’s Award for Excellence
The International Slurry Surfacing Association (ISSA) recognized the exceptional quality of MSI’s work by presenting the company with the 2012 President’s Award for Excellence. The award was given during ISSA’s 50th Annual Convention in Bonita Springs, Florida. The President’s Award recognizes contracting achievements that exemplify the highest quality of workmanship and compliance with the best standards of practice. Entries are judged on utility, appearance, schedule completion, customer satisfaction, and safety. MSI qualified for this prestigious award based on its outstanding performance on the I-70/I-270 project.
This project demonstrates how effective pavement preservation techniques, when paired with experienced contractors and careful project management, can deliver outstanding results even under the most demanding conditions. Agencies and contractors looking to adopt similar approaches can benefit from understanding How Cloud Based Project Management Software Helps Contractors coordinate complex multi-crew operations across large geographic areas.