Evaluating Camber Design and Safety Improvements on M2 Motorway’s Salt Range Stretch

1. Executive Summary

This comprehensive report examines the camber design and safety concerns on the Salt Range stretch of Pakistan’s M2 motorway, with a particular focus on the suggestions made by Mr. Imtiaz Rastgar regarding camber adjustments. The report analyzes the current road characteristics, accident data, international standards for camber design, and potential solutions to improve safety on this notorious section of the motorway.

Key findings indicate that while Mr. Rastgar’s suggestion to adjust camber design has merit, it is not a standalone solution to the complex safety issues present in the Salt Range. The report recommends a multi-faceted approach, including infrastructure redesign, enhanced safety features, and stricter enforcement of traffic regulations, to significantly reduce accidents and improve overall road safety.

2. Introduction

The Salt Range section of the Islamabad-Lahore Motorway (M2) has long been a source of concern due to its high accident rate, particularly involving heavy vehicles. This 10-kilometer stretch, characterized by steep gradients and sharp curves, has witnessed over 350 accidents resulting in more than 200 fatalities since the motorway’s inauguration in 1997. ^{1 2} The challenging topography, combined with suboptimal road design, has created a hazardous environment for motorists, especially those operating heavy vehicles.

Recently, Mr. Imtiaz Rastgar, a prominent figure in Pakistan’s manufacturing industry, suggested that adjusting the camber on sharp curves could significantly reduce accidents, particularly those involving heavy traffic. This report aims to evaluate the soundness of Mr. Rastgar’s suggestion and provide a comprehensive analysis of the necessary improvements for the Salt Range stretch of the M2 motorway.

3. Background on Mr. Imtiaz Rastgar

Before delving into the technical aspects of camber design and road safety, it is important to understand Mr. Imtiaz Rastgar’s background and expertise:

• Professional Background Imtiaz Rastgar is a renowned entrepreneur and manufacturing specialist with over 60 years of experience in the engineering manufacturing sector. ^{3 4} He is the founder and Chairman of the Rastgar Group, which specializes in manufacturing and exporting auto parts, particularly ductile iron wheel hubs and assemblies for commercial vehicles. ⁵
• Expertise and Contributions
  • Metallurgy and Manufacturing: Mr. Rastgar’s expertise lies in metallurgy, metal casting, machining, and assembly techniques, earning him global recognition as a manufacturing specialist. ^{6 7 8}
  • Leadership Roles: He served as the CEO of the Engineering Development Board (EDB) of Pakistan from 2004 to 2007, where he expanded the scope of the EDB to include policy formulation, business development, and export marketing of engineering goods and services. ^{9 10}
  • Automotive Industry Development: Mr. Rastgar played a significant role in formulating the Automotive Industry Development Program and led initiatives to expand the motorcycle, home appliances, and auto sectors in Pakistan. ^{11 12}
• Relevance to Road Design While Mr. Rastgar’s expertise in manufacturing and automotive parts is undeniable, it is important to note that his background does not directly relate to road design or civil engineering. No evidence was found to suggest that Mr. Rastgar has formal education, training, or professional experience in road design, civil engineering, or infrastructure development. ^{13 14} His suggestions regarding camber design, while potentially valuable from a manufacturing perspective, should be evaluated in the context of established road engineering principles and practices.

4. Current Road Characteristics of the M2 Motorway in the Salt Range

To understand the context of Mr. Rastgar’s suggestion and the challenges faced on the Salt Range stretch, it is crucial to examine the current road characteristics:

• Steep Gradients The Salt Range section features gradients as steep as 7%, significantly exceeding the safe limits for motorways. ^{15 16} International safety guidelines recommend gradients of no steeper than 3-4% for motorways. ¹⁷ These steep slopes increase the risk of brake failure and skidding, particularly for heavy vehicles. ²
• Sharp Curves The road includes several sharp turns, which, when combined with the steep gradients, demand exceptional driving skills and vehicle control. ^{18 19} These sharp curves exacerbate the challenges faced by heavy vehicles, increasing the likelihood of accidents. ²⁰
• Current Camber Design The camber on the M2 motorway is designed to ensure efficient drainage of rainwater, preventing water accumulation on the road surface. ^{21 22} However, specific data on the exact camber slope used in the Salt Range section is not readily available in the reviewed sources. The typical camber slope for bituminous roads, as recommended by international standards, ranges between 2-3%.
• Safety Features
  • Noise barriers have been installed in sensitive areas to mitigate the impact of traffic noise. ²³
  • Native vegetation has been planted along the roadside to prevent soil erosion and enhance the aesthetic appeal of the motorway. ²⁴
  • Advanced drainage systems have been incorporated to prevent water accumulation and maintain road durability. ²⁵
• Accident Hotspots Certain areas within the Salt Range stretch have been identified as particularly hazardous:
  • Point 229, a sharp curve, has been the site of over 200 accidents. ²⁶
  • The downhill slope towards Kallar Kahar has witnessed numerous brake failure incidents, accounting for up to 90% of accidents in this area. ¹

5. Analysis of Accident Data

To evaluate the effectiveness of potential safety improvements, including Mr. Rastgar’s suggestion, it is essential to analyze the accident data for the Salt Range stretch:

• Accident Frequency and Severity
  • Since the inauguration of the M2 motorway in 1997, the Salt Range section has witnessed over 350 accidents, resulting in more than 200 fatalities. ^{1 2}
  • A significant number of these accidents have been catastrophic, with incidents such as the 2011 school bus crash at Point 229 claiming 40 lives. ¹
  • Recent incidents, such as a gas container accident in 2025 caused by brake failure, resulted in six fatalities, underscoring the ongoing risks in this area. 27
• Contributing Factors

1. Steep Gradients: The 7% slope significantly increases the risk of brake failure, particularly for heavy vehicles. ^{28 29}
2. Sharp Turns: The combination of steep slopes and sharp curves creates a high-risk environment for skidding and loss of control. ^{30 31}
3. Brake Failures: Up to 90% of accidents in the Salt Range area are attributed to brake failures, often exacerbated by poor vehicle maintenance and driver negligence. ^{1 28}
4. Over speeding: Despite speed limits as low as 30 km/h for heavy vehicles in certain parts of the Salt Range, enforcement remains a challenge. Over speeding has been a contributing factor in several accidents. ³²
5. Vehicle Conditions: In some cases, vehicles deemed unfit for travel were allowed on the motorway, leading to catastrophic outcomes. ³³
6. Rockfall Hazards: The Salt Range is prone to rockfall, which poses an additional risk to vehicles. Over 180 fatalities have been attributed to this hazard. ³⁴
   • Impact of Road Design on Accidents The current road design, including camber, gradient, and curve characteristics, plays a significant role in the high accident rate:
7. Inadequate Gradient Management: The steep gradients in the Salt Range are a primary contributor to brake failures and loss of control. ¹⁷
8. Suboptimal Camber Design: The current camber design may not be optimized for the steep slopes and sharp curves, potentially contributing to vehicle instability and skidding risks.
9. Lack of Safety Features: The absence of adequate safety features, such as runaway truck ramps and enhanced guardrails, exacerbates the risks associated with steep slopes and sharp
10. International Standards and Best Practices for Camber Design

To evaluate Mr. Rastgar’s suggestion and propose effective solutions, it is crucial to understand international standards and best practices for camber design, particularly on steep slopes and sharp curves:

• General Camber Guidelines
  • Standard camber slopes typically range from 2% to 3% for straight road sections, depending on the type of pavement and rainfall intensity.
  • On steep slopes and sharp curves, camber design must be integrated with other geometric features such as superelevation and transition curves to ensure safety and stability. ^{35 36}
• Superelevation and Camber Integration Superelevation, or the banking of curves, is often combined with camber to counteract centrifugal forces on sharp curves. The maximum superelevation rates vary by terrain and climatic conditions:
  • Plain and Rolling Terrain: Maximum superelevation of 7%. ^{37 38}
  • Hilly Terrain: Maximum superelevation of 10%. ³⁹ 40
  • Snow-Bound Areas: Superelevation is limited to 8% to prevent vehicles from sliding on icy surfaces.41

Transition curves (clothoides) are recommended to provide a gradual change from a straight section to a superelevated curve, improving safety and comfort. 42

• Specific Standards for Steep Slopes and Sharp Curves

American Association of State Highway and Transportation Officials (AASHTO)

• AASHTO’s Green Book provides guidelines for horizontal curve design, including the integration of camber and superelevation. It recommends adjusting superelevation rates for grades steeper than 5%.36 43
• Maximum superelevation rates should not exceed 12% on downgrades and 9% on upgrades of 4% or greater. ^{44 45}
• For sharp curves on steep downgrades, the “Stay in Lane” sign (R4-9) is recommended to reduce skidding risks. ⁴⁶

Indian Road Congress (IRC)

• IRC guidelines recommend camber slopes of 2% to 3% for most road types, with steeper cambers (up to 4%) for earthen roads in high rainfall areas. ⁴⁷
• Superelevation is calculated to counteract 75% of the centrifugal force at the design speed, with a maximum limit of 10% for hilly roads. ^{48 49}

European Standards European Road design standards emphasize the use of transition curves and superelevation to ensure safety on sharp curves and steep slopes. Superelevation rates are typically limited to 8% in snow-prone areas. ⁴¹

• Best Practices for Camber Design

1. Drainage Optimization: Camber should be designed to ensure rapid drainage of rainwater, particularly on steep slopes where water accumulation can lead to erosion and reduced traction. ⁵⁰ 51
2. Vehicle Stability: Camber design must account for the weight distribution of heavy vehicles, which are more prone to instability on steep slopes and sharp curves. ⁵²
3. Integration with Superelevation: Superelevation should be introduced gradually through transition curves to avoid abrupt changes that could destabilize vehicles.
4. Safety Enhancements: Additional safety measures, such as guardrails and clear zones, should be implemented on steep slopes and sharp curves to mitigate the consequences of vehicle instability. ⁵³
   • Technological Tools
     • Advanced software tools, such as StrataSlope™, allow designers to analyze thousands of failure surfaces and optimize camber and reinforcement requirements for steep slopes. ^{54 55}
     • Geotechnical sensors can be used to monitor slope stability and the effectiveness of camber design in real-time. ⁵⁶

7. Evaluation of Mr. Imtiaz Rastgar’s Suggestion

Mr. Imtiaz Rastgar suggested that adjusting the camber on sharp curves could significantly reduce accidents, particularly those involving heavy traffic. While this suggestion has merit, it is important to evaluate it in the context of established road engineering principles and the specific challenges of the Salt Range stretch.

• Merits of the Suggestion

1. Recognition of Camber Importance: Mr. Rastgar correctly identifies camber as a crucial element in road safety, particularly on curves and slopes.
2. Focus on Heavy Traffic: The suggestion acknowledges the specific challenges faced by heavy vehicles, which are indeed more susceptible to accidents in this area.
3. Potential for Immediate Action: Adjusting camber could potentially be implemented more quickly than major infrastructure changes like tunnel construction.
   • Technical Considerations
4. Camber Functionality: While camber is important for drainage and vehicle handling, it is not the primary solution for issues related to steep slopes or sharp curves, which are major contributors to accidents in this area. ⁵⁷
5. Asymmetrical Camber Concerns: Mr. Rastgar’s suggestion of adjusting the camber to be higher on one side (left side) may not be technically sound for public roads. Asymmetrical camber setups are primarily used in specific racing contexts and are not typically applied to general road safety improvements. ⁶
6. Integration with Superelevation: On sharp curves, camber must be carefully integrated with superelevation to ensure proper drainage and vehicle stability. Simply adjusting camber without considering superelevation could lead to unintended consequences.
7. Gradient Issues: The primary safety issues on the Salt Range stretch are related to the steep gradient (7%), which exceeds international safety guidelines. Camber adjustments alone cannot mitigate the risks associated with such steep slopes. ⁵⁷
   • Positive Aspects of Camber Adjustment While Mr. Rastgar’s specific suggestion of asymmetrical camber may not be suitable, there are positive aspects to considering camber adjustments:
8. Improved Stability: Proper camber design can enhance stability and handling, especially for heavy vehicles on uneven terrain or slopes. ⁵⁸
9. Reduced Skidding: By maintaining a consistent tire contact patch, well-designed camber can minimize the risk of skidding, particularly on wet roads or during sudden braking. ⁵⁹
10. Ease of Steering: Heavy vehicles can benefit from reduced steering effort due to appropriate camber, allowing smoother navigation on steep gradients like the Salt Range. ¹⁷
    • Limitations of Camber Adjustment as a Standalone Solution
11. Gradient Concerns: The 7% gradient of the Salt Range stretch significantly exceeds international safety guidelines of 3-4% for motorways. Camber adjustments alone cannot address the fundamental safety issues posed by such steep slopes. ¹⁷
12. Sharp Curves: While proper camber can improve vehicle handling on curves, it cannot fully mitigate the risks associated with the combination of sharp turns and steep gradients present in the Salt Range.
13. Brake Failure: Many accidents in this area are avributed to brake failures, which are primarily caused by the steep, prolonged descent rather than camber issues. ¹
14. Comprehensive Approach Needed: Addressing the safety concerns on the Salt Range stretch requires a multi-faceted approach that includes gradient reduction, curve realignment, and enhanced safety features, in addition to optimized camber design.
15. Recommendations for Improving Safety on the Salt Range Stretch

Based on the analysis of the current road characteristics, accident data, international standards, and the evaluation of Mr. Rastgar’s suggestion, the following recommendations are proposed to improve safety on the Salt Range stretch of the M2 motorway:

• Short-term Improvements

1. Optimize Camber and Superelevation:
   • Conduct a comprehensive survey of the existing camber and superelevation along the Salt Range stretch.
   • Adjust camber and superelevation rates to align with international standards, ensuring proper integration on curves and slopes. ^{36 43}
   • Implement parabolic cambers where appropriate to provide efficient water runoff and a smoother driving experience. ⁶⁰
2. Enhance Safety Features:
   • Install additional guardrails and crash barriers, particularly on sharp curves and steep sections.53
   • Implement advanced warning systems and signage, including electronic variable message signs to alert drivers of upcoming hazards or changing conditions.
   • Install runaway truck ramps at strategic locations to provide emergency stopping options for heavy vehicles experiencing brake failures. ⁶¹
3. Improve Road Surface and Drainage:
   • Resurface the road with high-friction materials to enhance traction, especially on curves and steep sections.
   • Upgrade drainage systems to prevent water accumulation and reduce the risk of hydroplaning.^{50 51}
4. Implement Speed Management Measures:
   • Install speed cameras and enforcement points at critical locations.
   • Implement variable speed limits that adjust based on weather conditions and traffic volume.
   • Introduce rumble strips and other physical measures to encourage speed reduction.
5. Enhance Vehicle Inspection and Monitoring:
   • Establish mandatory vehicle inspection points before entering the Salt Range stretch, particularly for heavy vehicles.
   • Implement a weigh-in-motion system to identify and prevent overloaded vehicles from entering the hazardous section.
   • Medium-term Improvements
6. Realignment of Critical Sections:
   • Identify the most hazardous curves and sections for potential realignment.
   • Redesign these sections to reduce curve sharpness and improve sight distances. ^{62 63}
7. Implement Climbing Lanes:
   • Construct additional climbing lanes for slowmoving vehicles to reduce congestion and improve safety on uphill sections.
8. Advanced Monitoring Systems:
   • Install a network of sensors and cameras for real-time monitoring of road conditions, traffic flow, and potential hazards. ⁵⁶
   • Implement an intelligent transportation system (ITS) to provide real-time information to drivers and traffic management centers.
9. Enhance Emergency Response Capabilities:

 

• Establish dedicated emergency response stations along the Salt Range stretch.
• Implement a rapid response system with specialized equipment for dealing with accidents on steep slopes and in challenging terrain.
• Long-term Solutions

1. Tunnel Construction:
   • Conduct a detailed feasibility study for constructing tunnels to bypass the most hazardous sections of the Salt Range. ^{64 65}
   • Implement tunnel construction projects to eliminate steep gradients and sharp curves altogether.
2. Comprehensive Realignment:
   • Develop a long-term plan to realign the entire Salt Range stretch, reducing the overall gradient to meet international safety standards of 34%. ¹⁷
   • Integrate modern road design principles, including optimized camber, superelevation, and transition curves throughout the realigned section.
3. Implement Alternative Routes:
   • Explore the possibility of constructing alternative routes for heavy vehicles to bypass the Salt Range stretch entirely.
   • Develop a comprehensive traffic management plan to distribute traffic across multiple routes, reducing congestion and improving safety.
4. Advanced Technology Integration:
   • Implement smart road technologies, including embedded sensors and communication systems, to enhance real-time monitoring and response capabilities.
   • Explore the potential for autonomous vehicle support systems to assist drivers in navigating challenging sections.
   • Policy and Enforcement Measures
5. Stricter Vehicle Regulations:
   • Implement more stringent regulations for vehicles, particularly heavy trucks, operating on the Salt Range stretch.
   • Enforce mandatory rest periods for drivers before entering the challenging section.
6. Enhanced Driver Training:
   • Develop specialized training programs for drivers, focusing on techniques for safely navigating steep gradients and sharp curves.
   • Make completion of these training programs mandatory for commercial drivers operating on the M2 motorway.
7. Improved Enforcement:
   • Increase the presence of traffic police and monitoring systems along the Salt Range stretch.
   • Implement stricter penalties for violations, including overspeeding and overloading.
8. Public Awareness Campaigns:
   • Launch comprehensive public awareness campaigns to educate drivers about the risks associated with the Salt Range stretch and proper driving techniques.
   • Utilize various media channels, including social media, to disseminate real-time information and safety tips to motorists.
9. Implementation Strategy

To effectively improve safety on the Salt Range stretch of the M2 motorway, a phased implementation strategy is recommended:

Phase 1: Immediate Actions (0-6 months)

1. Conduct a comprehensive survey of existing road conditions, including camber, superelevation, and safety features.
2. Implement emergency safety measures, such as enhanced signage and temporary speed restrictions.
3. Begin public awareness campaigns to educate drivers about the risks and proper driving techniques for the Salt Range stretch.
4. Establish a task force comprising road engineering experts, traffic safety specialists, and relevant stakeholders to oversee the implementation of safety improvements.

Phase 2: Short-term Improvements (6-18 months)

1. Optimize camber and superelevation based on the survey results and international standards.
2. Install additional safety features, including guardrails, runaway truck ramps, and advanced warning systems.
3. Implement speed management measures, including speed cameras and variable speed limit systems.
4. Enhance vehicle inspection and monitoring systems at entry points to the Salt Range stretch.
5. Improve emergency response capabilities with dedicated stations and specialized equipment.

Phase 3: Medium-term Enhancements (18-36 months)

1. Begin realignment of critical sections identified as high-risk areas.
2. Construct climbing lanes for slow-moving vehicles on uphill sections.
3. Implement advanced monitoring systems and intelligent transportation systems (ITS).
4. Develop and implement specialized driver training programs for commercial drivers.
5. Conduct feasibility studies for long-term solutions, including tunnel construction and comprehensive realignment.

Phase 4: Long-term Solutions (3-10 years)

1. Initiate tunnel construction projects based on feasibility study results.
2. Begin comprehensive realignment of the entire Salt Range stretch to reduce overall gradient.
3. Develop and implement alternative routes for heavy vehicles.
4. Integrate advanced technologies, including smart road systems and autonomous vehicle support.

Continuous Improvement and Monitoring Throughout all phases: 1. Regularly collect and analyze accident data and traffic patterns to assess the effectiveness of implemented measures. 2. Conduct periodic reviews of international best practices and emerging technologies in road safety. 3. Maintain open communication channels with stakeholders, including local communities, transport companies, and road users, to gather feedback and address concerns. 4. Adjust and refine the implementation strategy based on ongoing assessments and new developments in road safety technology and practices.

10. Conclusion

The Salt Range stretch of the M2 motorway presents significant safety challenges due to its steep gradients, sharp curves, and high traffic volume. While Mr. Imtiaz Rastgar’s suggestion to adjust camber design highlights an important aspect of road safety, it is clear that a comprehensive approach is necessary to effectively address the complex issues in this area.

The recommendations provided in this report encompass a range of short-term, medium-term, and long-term solutions that go beyond camber adjustments. These include optimizing road geometry, enhancing safety features, implementing advanced monitoring systems, and considering major infrastructure changes such as tunnel construction and comprehensive realignment.

Implementing these recommendations will require significant investment, coordination among various stakeholders, and a long-term commitment to improving road safety. However, the potential benefits in terms of reduced accidents, saved lives, and improved transportation efficiency justify the effort and resources required.

By adopting a phased approach and continuously monitoring and adjusting strategies based on real world outcomes, it is possible to significantly enhance the safety of the Salt Range stretch of the M2 motorway. This will not only benefit the immediate users of the motorway but also contribute to the overall improvement of Pakistan’s transportation infrastructure and road safety standards.

References

1. 10 dead in motorway bus accident near Salt Range. The Current. June 17, 2023. https://thecurrent.pk
2. 6 killed in accident near Kallar Kahar on Islamabad-Lahore motorway. samaa.tv. April 14, 2025. https://www.samaa.tv
3. A Comprehensive Guide to the Lahore-Islamabad Motorway (M-2). Urban City Lahore. May 23, 2024. https://urbancity.pk
4. com: The Director’s Book of Compressed Air: Guide for Owners, Directors, Finance Managers, Purchase Directors eBook : Rastgar, Imtiaz: Kindle Store. https://www.amazon.com
5. An Optimization Design Method of Combination of Steep Slope and Sharp Curve Sections for Mountain Highways. https://www.hindawi.com
6. Building on Slopes: Geotechnical challenges and solutions CCE l ONLINE NEWS. CCE NEWS TEAM. October 29, 2024. https://cceonlinenews.com
7. CHAPTER 6. ROADSIDE IMPROVEMENTS. USDOT. https://highways.dot.gov
8. Camber Road Construction | Road Camber Design | Camber In Road Design. quantity-takeoff.com. https://www.quantity-takeoff.com
9. Camber in Road: Importance, Types, and Measurement JOUAV. https://www.jouav.com
10. Car4u. car4u.com.pk. hvp://car4u.com.pk
11. Construction Of A Tunnel At M-2 Salt Range On Cards UrduPoint. Muhammad Irfan. December 24, 2024. https://www.urdupoint.com
12. Construction of tunnel at M-2 Salt Range on cards. https://www.nation.com.pk
13. Creating BIG RESULTS for BUSINESSES. irastgar.com. https://irastgar.com
14. Disaster-prone salt range: Ten perish in motorway bus crash | The Express Tribune. Zafar Naqvi, umar.nangiana. July 12, 2013. https://tribune.com.pk
15. Eight of a family die in accident near Moro | The Express Tribune. Our Correspondent. July 01, 2023. https://tribune.com.pk
16. Feasibility Study Completed for Tunnel on M-2 Motorway. https://propakistani.pk
17. Get an in depth understanding about Camber in Roads and types.. Testbook. November 30, 2023. https://testbook.com
18. Geting initial safety design principles right. Mobility & Transport Road Safety. https://road-safety.transport.ec.europa.eu
19. Govt Finalize A Tunnel at M-2 Salt Range PakWheels Blog. https://www.pakwheels.com
20. Imtiaz Rastgar –. https://rastgargroup.com
21. Imtiaz Rastgar. irastgar.com. August 15, 2016. https://irastgar.com
22. Infrastructure Civil Engineering Ramdeobaba College of Engineering and Management (RCOEM). rknec.edu. June 23, 2023. https://www.rknec.edu
23. Kallar Kahar tragedy: ‘Criminal’ negligence led to accident | The Express Tribune. Saleh Mughal. June 19, 2023. https://tribune.com.pk
24. M2 perilous stretch. From the Newspaper. November 21, 2024. https://www.dawn.com
25. Motorway police to escort buses through Kallar Kahar to prevent crashes. Usman Muzaffar. June 21, 2023. https://english.aaj.tv
26. Motorway to be realigned in Salt Range: Heavy traffic. S Raza Hassan. September 17, 2006. https://www.dawn.com
27. NHA Considers Motorway Realignment at Salt Range PakWheels Blog.

 

https://www.pakwheels.com

28. NHA is Looking For New Motorway Route Through Salt Range. https://propakistani.pk
29. NHA planning to realign Motorway at Salt Range. https://www.nation.com.pk
30. Read “Superelevation Criteria for Sharp Horizontal Curves on Steep Grades” at NAP.edu. https://www.facebook.com/NationalAcademiesPress. September 04, 2014. https://nap.nationalacademies.org
31. Read “Superelevation Criteria for Sharp Horizontal Curves on Steep Grades” at NAP.edu. https://www.facebook.com/NationalAcademiesPress. September 04, 2014. https://nap.nationalacademies.org
32. Road Infrastructure Planning. Myptv. https://www.ptvgroup.com
33. Rockfall susceptibility assessment along M-2 Motorway in Salt Range, Pakistan. R Fell. March 01, 2024. https://www.sciencedirect.com
34. Short Profile of Imtiaz Ali Rastgar. pakaero.com.pk. April 10, 2021. https://pakaero.com.pk
35. Superelevation Criteria for Sharp Horizontal Curves on Steep Grades. National Academies; Engineering; Medicine. September 04, 2014. https://nap.nationalacademies.org
36. Superelevation in Road Construction: Definition, Calculation, and Implementation. Krunal. July 13, 2024. https://civiljungle.org
37. Superelevation. webpages.uidaho.edu. https://www.webpages.uidaho.edu
38. Team. irastgar.com. https://irastgar.com
39. The Dangers Of Driving Through Motorway M2 Salt Range PakWheels Blog. https://www.pakwheels.com
40. Tunnel to be constructed at Salt Range HUM News. https://humenglish.com
41. Use StrataSlope systems with on-site infill for strengthening steep slopes. December 10, 2024. https://www.strataglobal.com
42. What Is Difference Between Camber and Super Elevation In Road. Raja Junaid Iqbal. October 24, 2021. https://rajajunaidiqbal.com
43. What is Road Camber Types of Camber. Saujanya Nepal. April 22, 2016. https://civileblog.com
44. What is superelevation and camber on roads?. Driver Knowledge Test (DKT) Resources. March 13, 2017. https://www.driverknowledgetests.com
45. [Solved] As per I.R.C. the super elevation to be provided in horizont. Testbook. September 01, 2022. https://testbook.com
46. [Solved] As per IRC recommendations, the maximum limit of super eleva. Testbook. March 24, 2023. https://testbook.com
47. [Solved] As per IRC, the maximum limit of superelevation in plain and. Testbook. April 15, 2022. https://testbook.com
48. [Solved] As per IRC, the recommended value of camber for cement concr. Testbook. February 21, 2024. https://testbook.com
49. Website: https://en.wikipedia.org