India’s highways continue to expand at a healthy pace. But conversations on the surface quality of highways are growing louder because major deficiencies and black spots continue to be identified, and they are cause for concern.“Road surface roughness causes vehicle vibrations that, in turn, can affect the performance of drivers,” explains Dr V K Gahlot, Road Safety Auditor, Centre for Research and Sustainable Development (CfRSD). “Continuous exposure may induce fatigue, a contributory factor to road accidents. Road surface roughness also affects the vehicle operating cost.”CW turned to the industry for opinions on why surface quality has become an issue, the role of paving and compaction, and what should be done to improve the situation.Design flawsMinister of Road Transport and Highways Nitin Gadkari has called out poor detailed project reports (DPRs) and the Indian Road Congress for quality lapses.The minister’s concern is well-founded, according to Atasi Das, Assistant Vice President, GR Infraprojects. “Many DPRs are based on limited or poor-quality soil investigations, fail to anticipate escalating traffic load and volume, and overlook critical environmental conditions such as rainfall and temperature extremes,” she explains. “Such deficiencies result in inherently flawed designs.”Attributing poor riding quality to a confluence of design, execution and maintenance failures, Pranav Saraswat, Senior Research Fellow, Department of Civil and Infrastructure Engineering, Indian Institute of Technology - Jodhpur, explains that design errors are largely misjudgements. For instance, “over-relying on empirical designs (IRC:37) without thorough field investigations leads to under-designed pavements.”“Inadequately providing for surface and subsurface drainage causes water to stagnate and weakens the base and sub-base layers,” he adds. “Ignoring climate-responsive materials or traffic overloading realities in states like Rajasthan or Punjab causes poorly designed highways.”Undesirable shortcutsMultiple interrelated systemic issues also have a hand in the subpar riding quality on Indian highways, says Das. “The current L1 (lowest bid) procurement model compels contractors to take shortcuts to remain financially viable, often at the expense of quality. Aggressive 18-24 -month schedules for greenfield highway projects also often force contractors to sidestep key engineering processes.”What are these shortcuts and side-stepped processes?“Improper compaction during construction can lead to uneven surfaces and premature deterioration,” says Dr Gahlot. “Compaction eliminates air voids and increases the density of materials, enhancing their strength and load-bearing capacity and reducing the likelihood of uneven settlement or rutting, leading to a smoother, more stable ride.”Saraswat points out that inadequate compaction, moisture control or poor material selection (such as plastic clay or expansive soils left untreated) cause differential settlements and surface undulations. Inconsistent layer thickness and poor gradation in the granular sub-base and wet-mix macadam result in non-uniform support.Inadequate compaction includes skipping rolling passes, using worn-out rollers or compacting at suboptimal temperatures, adds Saraswat. “Skipping layer-wise testing for density, thickness, bitumen content and so on is another concern.”“Compaction energy must be applied progressively,” explains Das. “If high vibration is applied during initial passes, only the top few millimetres of the layer are compacted while the remaining lower thickness remains loose. This results in a structurally weak base, even if advanced equipment is used.”While much is being said about intelligent compactors that can log every pass, she points out that the lack of onsite internet connectivity or data interpretation skills leaves such information unused. Consequently, shortcuts like reducing compaction passes continue.Side-stepped processesCompromising essential procedures like natural soil consolidation and full concrete curing (which requires 28 days for optimal strength) undermines long-term pavement performance as weaker concrete is prone to early-age cracking, adds Das. “Sometimes, embankments are constructed in single thick layers (>500 mm), whereas IRC standards limit this to 250 mm per layer. Moreover, insufficient time is allowed for soil consolidation, leading to post-construction settlement and surface undulations.”According to Saraswat, “Inadequately curing the prime coat before placing the wet-mix macadam, using pavement material without proper gradation and binder correction, and cold joints in bituminous layers due to poor planning or non-continuous paving are associated with poor surface outcomes.”“Longitudinal waviness, rutting or shoving in the bituminous layers occur when the paver settings (incorrect screed temperature, grade sensors) are incorrect, or the compaction is delayed or inadequate, especially when the paving occurs at night or during peak seasons,” he adds. “Poor control of temperature differentials causes thermal segregation.”Substandard materialsSubstandard materials are a kind of shortcut in the sense that they cost less than standard materials.“Lower-cost, inferior aggregates and reduced bitumen content are commonly used to cut costs, severely impacting the pavement’s strength and longevity,” observes Das.“Using substandard bitumen or aggregates, sometimes mixed with dust or coated particles, and an overdiluted or absent tack coat or poor bonding between layers lead to slippage and delamination under traffic,” continues Saraswat. Inexperienced manpowerA significant skill gap, particularly at the grassroots level where operators are often ill-equipped to manage sophisticated automated equipment effectively, is also to blame for poor surfaces, says Das. “When the underlying soil is still settling or the operators lack adequate training, the benefits of sophisticated equipment like GPS-guided pavers and intelligent compactors are nullified.”Inexperienced manpower and, resultantly, poor onsite engineering supervision, improper quality control (quality control registers filled post-facto, labs under-equipped), and in some stretches, bituminous mix designs not verified onsite or modified to suit local materials are some other concerns, according to Saraswat.Systems-level reformConsidering that India’s highway pavement quality challenges stem from a fundamental mismatch between engineering requirements and project delivery models, Das stresses the need to incorporate realistic timelines in project bids. “Allowing for natural consolidation of earthwork and adequate curing time for concrete is a crucial engineering parameter that no machine can bypass,” she says.Material and construction quality control should be improved by enforcing real-time density testing using non-destructive methods or core cutting, using thermal imaging and GPS-enabled pavers for better temperature and layer control, and mandating the traceability of the source of bitumen and regular performance grading, says Saraswat. “Specifying straightedge and rolling straightedge compliance for longitudinal and transverse unevenness would help.”“Instead of just mandating automated pavers and compactors, the NHAI should enforce the use of their data in real time,” says Das. “The provision of reliable Wi-Fi and Internet at sites needs to be a mandatory, budgeted item in the bid documents to enable this.”Improving accountabilityA shift from ‘specification-based’ to ‘performance-based’ design and monitoring, as described in IRC:SP:84 or the NHAI’s new EPC standards, is the need of the hour, according to Saraswat. “Performance-based evaluation would include post-construction audits based on the International Roughness Index (IRI), rut depth and deflection under the deflection-based maintenance model, and would penalise contractors under the defect liability period for early deterioration or failure to meet ride quality metrics.”Das proposes a shift from the L1 system to a model where a portion of the payment is tied to the road’s performance (riding quality, durability etc.) for a few years after completion. “The need now is not just specification but on-ground accountability and digital tracking of lifecycle performance,” explains Harshvardhan Sharma, Group Head for Auto Tech and Innovation, Nomura Research Institute Consulting & Solutions India. “While our specifications are largely sound, consistent execution across regions is often hampered by supervision and visibility impediments. On-ground accountability means enhancing how we monitor and enforce quality standards – not just during construction, but throughout the asset’s early lifecycle.” To drive greater project-level accountability, he suggests the implementation of independent audits, structured quality scoring for contractors and public-facing dashboards.Saraswat emphasises the need to strengthen independent third-party quality audits and remove conflicts of interest in QC/QA reporting; the use of digital construction monitoring tools such as drones, AI-based profiling and IoT sensors; and necessitating training and certification for site engineers, operators and supervisors.Sharma cites the Ministry of Road Transport and Highways’ Road Asset Management System (RAMS) as a step in the right direction. “RAMS is beginning to build a centralised view of highway assets but adoption remains in the nascent phase for now,” he notes. “Various start-ups like RoadMetrics and RoadAthena are also making promising progress – leveraging smartphone-based data capture, AI and video analytics to detect surface distress and map quality across both urban and highway networks.”On the global front, Sharma highlights Japan as a benchmark. “Japanese authorities are using integrated asset visualisation platforms that combine LIDAR scans, vehicle-mounted sensors and GIS-linked deterioration models to proactively manage road health,” he explains. “This approach emphasises both data integrity and actionability, with insights feeding directly into multi-year maintenance plans. India could benefit greatly from institutionalising such predictive frameworks, especially as its road network continues to expand.”Indeed, that is the goal: Upholding quality as the highway network expands. Measuring the quality of roads Riding quality is technically measured via the International Roughness Index (IRI) and, qualitatively, through user perception. The Roughness Index measures road roughness in terms of vertical displacement per unit of distance, explains Dr V K Gahlot, Road Safety Auditor, Centre for Research and Sustainable Development (CfRSD). Ideally, the roughness index of new roads should be less than 1.2 m/km. When the index touches 4 m/km, the road needs to be maintained such that the index drops to below 2.2 m/km.QuotesContinuous exposure to road surface roughness may induce fatigue, a contributory factor to road accidents. - Dr V K Gahlot, Road Safety Auditor, Centre for Research and Sustainable DevelopmentA confluence of design, execution and maintenance failures is behind poor riding quality. - Pranav Saraswat, Senior Research Fellow, Department of Civil and Infrastructure Engineering, Indian Institute of Technology - JodhpurThe need now is not just specification but on-ground accountability and digital tracking of lifecycle performance. - Harshvardhan Sharma, Group Head for Auto Tech and Innovation at Nomura Research Institute Consulting & Solutions IndiaIndia’s highway pavement quality challenges stem from a fundamental mismatch between engineering requirements and project delivery models. - Atasi Das, Assistant Vice President, GR Infraprojects- Charu Bahri