Road Rehabilitation or Resurfacing? How to Define the Right Treatment Scope Before Tendering

Decision-makers in municipalities and asset-owning entities, as well as infrastructure project managers, face a recurring dilemma when deterioration is detected across a road network: should they limit the treatment to milling the surface course and resurfacing to reduce costs and accelerate completion, or should they reconstruct and rehabilitate the entire pavement structure?

Making the wrong decision at this stage can cost public entities millions of Saudi riyals. Applying a surface treatment to a road suffering from failure within its granular base layers represents a clear waste of funds, as cracks and surface deformation will reappear within a few months through a phenomenon known as reflective cracking.

Conversely, selecting a comprehensive structural solution for a road that only requires renewal of its wearing course results in an unjustified depletion of financial resources and unnecessary disruption to traffic.

Contractual success depends on defining the scope of work accurately before issuing the tender and selecting the engineering intervention that achieves the optimal balance between total cost and long-term functional performance. This guide explains the engineering standards and protocols applied in Saudi Arabia to support accurate and reliable treatment decisions.

The choice between surface resurfacing and road rehabilitation projects is determined by the structural assessment of the deeper pavement layers. If the defects are limited to oxidation, roughness, and minor surface cracking, while the base layers remain sound—with a PCI value above 60 and no structural settlement—milling and resurfacing will generally be sufficient.

However, if Falling Weight Deflectometer testing and the International Roughness Index reveal wheel-path settlement, deformation of the granular base course, or deteriorated drainage, including the project within a road rehabilitation scope becomes essential to ensure pavement sustainability and prevent structural failure.

Executive Summary for Municipal Officials and Tender Committees

• Applying surface resurfacing to a road with structural weakness in its base layers can result in treatment failure exceeding 80% within the first two years after completion.
• The Pavement Condition Index, together with Falling Weight Deflectometer testing, provides the scientific basis for distinguishing between functional and structural defects.
• A 20-year Life-Cycle Cost Analysis helps demonstrate the economic feasibility of road rehabilitation projects compared with repeated resurfacing.
• The Saudi Road Code requires rehabilitation decisions to be linked to inspections of groundwater drainage systems and buried utilities to prevent newly laid asphalt from being excavated after the road is reopened.

1. Distinguishing Between Functional and Structural Pavement Failure

Preparing an accurate tender document begins with a clear understanding of the type of pavement deterioration involved.

A road may lose its ability to provide motorists with a safe and comfortable driving experience. This condition is technically referred to as functional failure. It may appear as surface roughness, aggregate polishing and reduced skid resistance, or asphalt bleeding.

This type of deterioration can generally be treated through surface resurfacing, also known as milling and overlaying, with a typical thickness of 4–5 centimetres without disturbing the lower pavement layers.

Structural failure, by contrast, means that the entire pavement structure—including the asphalt, base course, and subbase—is no longer capable of supporting increasing traffic volumes and axle loads.

This failure is reflected in extensive alligator cracking, deep wheel-path rutting, and settlement caused by weak subgrade soil or water infiltration. In such cases, patching solutions fail completely, and structural road rehabilitation becomes essential to address the root cause of the problem at depth.

2. Engineering Decision Matrix: When Should You Resurface and When Should You Rehabilitate?

To determine the treatment scope objectively and minimise contractual disputes and variation orders, road engineers apply the following technical criteria:

3. Decisive Field and Laboratory Tests for Defining the Treatment Scope

Tender committees should not rely solely on visual inspection when preparing bills of quantities. Sound engineering practice requires a package of preliminary tests to define the road rehabilitation scope accurately.

A. Falling Weight Deflectometer Testing

The Falling Weight Deflectometer is the most important non-destructive test used to evaluate pavement structural strength.

The device applies a dynamic load that simulates the wheel load of a heavy vehicle. Sensors then measure the deflection and recovery of the pavement layers.

These measurements are used to calculate the resilient modulus of each layer and determine whether the granular base course remains structurally stable or has deteriorated and requires rehabilitation.

B. Coring and Test Pits

• Cylindrical asphalt samples are extracted to determine crack depth and identify whether the cracks are top-down cracks that can be treated through milling or bottom-up fatigue cracks that require the entire pavement structure to be removed.
• Test pits are excavated to reach the base course and subgrade. Moisture content and particle-size distribution are measured, and California Bearing Ratio tests are conducted to confirm whether the soil can support current traffic loads.

C. International Roughness Index

Laser-equipped survey vehicles are used to calculate the International Roughness Index, which indicates ride quality.

A high IRI value provides clear evidence of deformation in the road’s longitudinal profile and may require comprehensive levelling and elevation correction.

4. Infrastructure and Drainage: The Decisive Factors in Rehabilitation

Failure to inspect conditions beneath the road is one of the primary causes of asphalt-project failure in Saudi Arabia.

If underground water networks are leaking, or stormwater drainage systems are absent or blocked, any newly constructed pavement will deteriorate rapidly as the granular materials become saturated.

An integrated road rehabilitation scope requires the following corrective works to be completed before the pavement layers are installed:

1. Drainage-system treatment: Construct longitudinal underdrains surrounded by geotextile to remove subsurface water and reduce groundwater levels around the pavement base course.
2. Coordination and upgrading of buried utilities: Coordinate with water, electricity, and telecommunications providers to replace deteriorated services and install future utility ducts, preventing the need for permits to excavate and cut newly laid asphalt only a few months after the road opens.
3. Subgrade stabilisation and improvement: Use cement, lime, or bitumen-emulsion stabilisation techniques, including Full Depth Reclamation, to improve weak soil-bearing capacity without fully excavating and replacing the existing materials.

5. Economic Considerations and Life-Cycle Cost Analysis

When comparing quotations and scopes of work, some procurement officials make the mistake of focusing solely on the initial capital cost. Surface resurfacing may initially appear to be the least expensive and most attractive option.

However, applying a Life-Cycle Cost Analysis over 20 years may demonstrate the opposite:

• Surface resurfacing over a weak base: This scenario may require milling and resurfacing every three to five years, together with increasing annual patch-repair costs and indirect losses caused by traffic disruption and vehicle damage. The cumulative cost may eventually exceed twice the original construction cost.
• Comprehensive structural road rehabilitation: This option requires a higher initial investment but can provide a design service life of 15–20 years with limited routine preventive maintenance, delivering a stronger return on investment in the asset owner’s infrastructure.

6. Compliance with the Saudi Road Code and Official Specifications

Maintenance and rehabilitation work on Saudi road networks is subject to mandatory technical governance issued by the relevant regulatory authorities:

• Saudi Road Code: Defines the minimum acceptable structural and operational performance levels for different road classifications, including arterial, collector, and local roads. It also specifies engineering requirements for compaction ratios, asphalt-binder viscosity, and asphalt-recycling controls.
• Ministry of Municipalities and Housing specifications and the Balady platform: Require compliance with building-compliance certificates and site-coordination requirements. They also require the levels of manhole covers and stormwater inlets to be aligned with the final pavement surface to prevent traffic impact and water accumulation.
• Ministry of Transport and Logistics Services requirements: Require compliance with statutory axle-load limits to prevent the premature deterioration of newly rehabilitated pavement structures and the use of Polymer-Modified Asphalt in heavy-load routes and hot-climate regions.

7. Infrastructure and Road Rehabilitation Solutions with MEPCO

Major rehabilitation projects require a contractual partner with comprehensive engineering and field capabilities. The contractor must be able to assess structural conditions accurately and coordinate the complex interfaces between soil, utilities, and pavement layers.

MEPCO provides these capabilities through its General Contracting and infrastructure services. Clients receive integrated solutions covering site assessment, milling and recycling work, deep earthwork grading, and the placement of approved asphalt mixtures in accordance with leading national quality standards.

MEPCO’s execution capabilities are integrated with its Metal Industries and Fabrication division, which provides advanced manufacturing solutions for road crash barriers, stormwater drainage grates, supporting steel structures, and road signs that comply with Saudi specifications.

This in-house integration enables MEPCO to maintain greater control over project schedules, manage supply chains effectively, and provide high-quality handover outcomes that enhance the efficiency and safety of road transport networks.

8. Checklist for Reviewing the Scope of Work Before Tendering

Before approving the specifications and issuing a road maintenance or rehabilitation tender, confirm that the following preparatory steps have been completed:

• Has a comprehensive visual survey been conducted and the Pavement Condition Index calculated for every road section?
• Have Falling Weight Deflectometer tests and asphalt coring been completed to determine the depth of deterioration?
• Has the condition of surface and subsurface drainage networks been verified, and have the required treatments been included in the bill of quantities?
• Has coordination been completed with infrastructure committees and utility providers to inspect buried services and avoid conflicts?
• Have the milling depth and Polymer-Modified Asphalt specifications been clearly defined in accordance with the Saudi Road Code?
• Do the tender documents include detailed traffic-diversion plans and approved site-safety procedures?
• Have clear requirements been included for field-density testing and surface-evenness testing using a straightedge or laser equipment?

9. Conclusion and Call to Action

Making the correct decision between surface resurfacing and road rehabilitation before tendering is essential for rationalising public expenditure, protecting infrastructure assets, and achieving high standards of road safety.

Engineering tests and a comprehensive assessment of the base layers enable the project owner to prepare clear tender specifications, prevent contractual disputes, and award the project on a sound technical basis that supports pavement sustainability for decades.

If you are preparing a scope of work or tender for a road development or rehabilitation project and require a general contracting partner with integrated experience in infrastructure, paving, and supporting fabrication, contact MEPCO’s engineering team to discuss the technical requirements and obtain a specialised assessment that supports the success and sustainability of your investment.

Frequently Asked Questions About Road Rehabilitation

Q1: What Pavement Condition Index requires a transition to structural road rehabilitation?

The Pavement Condition Index is measured on a numerical scale from 0 to 100 in accordance with ASTM D6433.

If the PCI falls below 45–50 and structural defects such as rutting and extensive alligator cracking are present, surface maintenance loses its economic viability. A comprehensive structural rehabilitation project then becomes necessary to address the deterioration at its source.

Q2: What are the risks of only milling and resurfacing a road with a weak base course?

Milling the surface and applying new asphalt over an unstable base can lead to reflective cracking.

Under traffic loads and temperature changes, cracks and defects in the base course migrate into the new asphalt layer within a few months. This causes rapid pavement failure and wastes the entire treatment budget.

Q3: When is Full Depth Reclamation an ideal road rehabilitation solution?

Full Depth Reclamation is an effective engineering and economic solution when the asphalt and granular base course have lost their structural load-bearing capacity.

The full asphalt layer and part of the base course are milled and mixed on-site with binding materials such as cement or bitumen emulsions. This produces a strong and consistent stabilised base layer without transporting demolition waste or importing entirely new materials.

Q4: How do heavy-vehicle axle loads affect the selection of a road treatment?

Equivalent Single Axle Loads determine the cumulative stress imposed on the pavement.

If a road serves a logistics or industrial area with frequent heavy-truck traffic, conventional surface resurfacing may not withstand the resulting shear and compressive forces. Structural rehabilitation may therefore be required to increase the thickness and capacity of the base layers and introduce Polymer-Modified Asphalt capable of resisting rutting.

Q5: What role does the Saudi Road Code play in defining the treatment scope for municipal projects?

The Saudi Road Code establishes mandatory requirements for structural performance, material quality, compaction ratios, and quality-control testing.

It also defines standard methods for determining the causes of deterioration and assessing indicators such as the International Roughness Index and Falling Weight Deflectometer results. Compliance with the code standardises project acceptance and handover criteria and prevents arbitrary estimates in government and municipal tender documents.