What has the government mandated for service roads and slip roads along highways?
MoRTH’s new guidelines require service roads and slip roads along national highways to follow the same design parameters as the main carriageways. Until now, there were no standard norms for service roads, resulting in thinner road surfaces and more potholes.
Under the new rules, service roads must be designed taking into account the same base traffic, traffic growth rate, vehicle damage factor and axle-load assumptions as the main highways. The minimum road surface thickness has been fixed, regardless of traffic estimates. In several cases, rigid (concrete) road surfaces have been made mandatory.
The norms will apply to new highway projects and ongoing projects where strengthening is required.
Why is MoRTH insisting on main-carriageway standards for service roads?
The change reflects a stark reality: service roads often function as the main traffic lanes. During highway construction, repair work, lane closures or traffic surges, vehicles including heavy trucks are diverted onto service roads. However, these roads were never designed to handle such loads, leading to rapid surface failure, potholing and safety hazards.
Frequent maintenance of service roads slows the pace of construction of main highways. By strengthening service roads, the government expects fewer traffic diversions during construction, faster execution of highway projects and fewer long-term maintenance disruptions.
What do the new standards mandate?
The guidelines lay down detailed and non-negotiable specifications. The life of service roads will be equal to the project construction period in years plus six years.
In terms of traffic load, the assumptions are the same as for the main carriageway, with a minimum of 20 million standard axles for the road surface. A standard axle is the reference load used to measure pavement damage.
The ministry has specified the minimum thickness of road surfaces, or pavements. There are three categories of pavements—flexible (bituminous/black top surface), rigid (concrete top) and composite (a cement concrete base or slab covered by a bituminous surface).
Rigid pavements are mandatory in high rainfall areas (over 1,500 mm annually) and stretches prone to waterlogging, urban and industrial zones, defence areas, mining belts, special economic zones and economic corridors.
Drainage must comply with the standards and guidelines set by the Indian Roads Congress, the premier technical body of highway engineers and professionals that provides a standardized, research-backed framework for all aspects of road and bridge construction in the country.
Crucially, service roads must be completed before work begins on main carriageways.
How will the new norms affect the cost of highway projects?
Building service roads to the same standards as main carriageways means thicker pavement crusts, higher material consumption (bitumen, aggregates, cement), longer construction timelines before the main highway work can begin and increased upfront capital expenditure for developers. Experts said this could materially increase project costs, especially in urban stretches where service roads are located on both sides and rigid pavements are mandated.
As Kuljit Singh, partner and national infrastructure leader at EY India, pointed out: “Building service roads to main carriageway standards means they would need to be stronger to bear similar axle loads. This inevitably increases costs. Ideally, pavement design should account for lower traffic on service roads.”
Highway construction costs in India vary by project type but typically, constructing a four-lane highway would cost ₹15-20 crore per km.
Who bears the cost in PPP highway projects?
In public-private partnership (PPP) projects, the cost burden will fall squarely on the developers—at least initially.
There are several implications: higher bid costs in future highway tenders, potential pressure on financial viability, especially in tolled projects, renewed calls for better risk-sharing in revised model concession agreements, and possible recalibration of traffic and cost assumptions by lenders. There is also a revenue-side risk.
“Better-built service roads could divert some vehicles away from tolled carriageways, impacting toll collections—especially where local traffic can bypass toll plazas,” said Jagannarayan Padmanabhan, senior director and global head, consulting at Crisil Intelligence.
This could influence how toll roads are valued under toll-operate-transfer and InvIT monetization models.
Will the long-term benefits justify the higher costs?
From the government’s perspective, yes—provided execution improves. Stronger service roads could reduce construction delays caused by repeated repairs. Besides, such roads would improve safety during highway expansion, lower lifecycle maintenance costs and enable faster completion of main carriageways.
However, the policy’s success will depend on how costs are absorbed—whether through revised project pricing, improved monetization returns, or contract reforms that acknowledge the higher capital requirement. For now, the message from MoRTH is clear: service roads are no longer secondary infrastructure. They are an integral part of highway capacity—and will now be built, priced and regulated accordingly.