A Practical Guide to Using Krishna and Arunarani's Highway Engineering Textbook
I keep running into students and junior engineers who treat this book as a reading exercise rather than a reference tool, which is a mistake. The 4th edition by Seshagiri Krishna and Arunarani Arasan is one of the more widely used highway engineering textbooks in Indian universities and among practicing engineers who need a solid foundation before moving to design software. It covers the fundamentals of highway planning, geometric design, traffic engineering, and pavement analysis in enough depth that you will likely consult it throughout your career, not just during coursework. Here is how I actually use this book when I need answers, and what to watch out for when you work through it. The book is organized into roughly six major parts: introduction to highway engineering, highway surveys and planning, geometric design, traffic engineering, pavement design, and drainage. The first five chapters alone establish the survey and planning framework that most people skim too quickly. Chapter 2 on reconnaissance, location, and survey of highways contains tables for desirable and minimum values of geometric elements that you will need to memorize or keep at your fingertips. The revised 4th edition added updated traffic analysis content, but the core geometric design chapters still rely heavily on AASHTO values and IRC codes, so cross-referencing is necessary.
When I am solving a problem, I do not read the book cover to cover. I go straight to the chapter relevant to the calculation, study the worked examples, and then attempt similar problems. The worked examples in this edition are more numerous than earlier editions, which helps. The derivation of stopping sight distance and overtaking sight distance is clearly laid out, and the numerical examples follow IRC guidelines closely enough for exam purposes and basic practice.
Geometric Design: The Chapters You Will Return To
Chapters on horizontal alignment, vertical alignment, and intersection design are where this book earns its keep. The super-elevation and friction discussions are standard but well explained. One thing many people miss is that the textbook presents the compound curve and reverse curve design procedures with sufficient examples, yet beginners often conflate transition curve length computation with sight distance requirements. These are separate checks. You compute the transition curve length based on rate of change of centrifugal ratio or super-elevation runoff, whichever governs, and then verify stopping sight distance independently. I ran into a specific issue last year when a junior on my team was designing a rural highway section and used the minimum radius from the textbook table without adjusting for the design speed being lower than the posted design speed due to terrain classification. The table gives both desirable and minimum values, and the book does mention terrain categories, but it does not walk through the decision logic step by step. I had him go back to IRC SP: 36 for the terrain classification methodology, then recompute the radius and superelevation with the correct design speed. The error came from skipping the terrain-based design speed selection, not from any flaw in the book itself.
Get the Full Details
Traffic Analysis: Where the Book Is Useful and Where It Falls Short
The traffic engineering portion covers traffic volume studies, origin-destination surveys, parking studies, and traffic signal design. The four-step trip generation model is mentioned briefly, which is honest but insufficient for anyone doing actual transit or corridor planning. For academic problems, the book is adequate. For real-world trip generation rates, you will need supplementary sources like the ITE Trip Generation Manual or local transport authority guidelines. One counter-intuitive point that the book does not emphasize enough: when converting traffic volume to passenger car units, heavy vehicle adjustment factors depend heavily on grade percentage and length. Using a standard HV factor without considering the upgrade characteristics will under-predict capacity loss on hilly terrain. I have seen this mistake cost projects weeks of rework because the level-of-service analysis was done with flat-terrain adjustment factors on a 4 percent upgrade.
Pavement Design: What You Need to Know
The pavement chapters cover flexible and rigid pavement design principles, materials, and failure modes. The book explains CBR-based design and presents the IRC methods for flexible pavement thickness determination. For rigid pavement, it walks through Westergaard's stress calculations and IRC load stress combinations. The derivations are clear, but the book does not go deep into mechanistic-empirical approaches, which is a gap. If you are working on modern pavement projects, you should supplement this with AASHTO 1993 or the IRC 37 guidelines for flexible pavement and IRC 58 for rigid pavement design. A common pitfall: students often calculate the design thickness and stop there. They forget that subgrade CBR values must be validated with field plate bearing tests or laboratory tests on samples from the correct depth. Using an assumed CBR without site-specific data is one of the most frequent errors I see in project reviews. The book mentions this, but the examples use idealized values, which gives a false sense of precision.
Limitations of the 4th Edition
I want to be straightforward about what this book does not cover well. The 4th edition was published around 2016, and highway engineering has moved forward since then. Smart transportation systems, connected and autonomous vehicle implications for intersection design, and contemporary sustainability considerations in highway engineering are not addressed. The traffic forecasting chapters rely on traditional methods that are fine for academic problems but outdated for projects requiring advanced travel demand modeling. If you are doing a thesis or a capstone project that involves traffic simulation or modern design tools, you will need additional references. Another limitation: the book is oriented toward Indian design standards and practices. If you are studying for exams or working on projects in other countries, you will need to map the concepts to local codes. The fundamental physics and engineering principles translate, but the numerical values and code references will differ.
How to Actually Use This Book in Practice
I keep a copy on my desk and use it as a quick reference for formulas and standard values. When I need to verify a super-elevation calculation or check a sight distance chart, I open the relevant chapter, find the example closest to my problem, and adapt it. The process takes me about 10 to 15 minutes per calculation check, compared to searching through multiple code documents. For exam preparation, working through every numerical problem in each chapter will take you roughly 40 to 60 hours across the entire book, spread over two to three weeks if you are studying full time. If you are looking for the textbook, it is published by Prentice Hall India and available through major academic book retailers, Amazon India, and university bookstores. The ISBN is 978-93-325-1844-7. There are third-party PDF versions circulating online, but those are copyright violations and tend to have scanned quality issues that make reading equations frustrating.
Final Points That Matter
Use this book as a foundation, not as a complete reference for modern practice. Pair it with current IRC codes, AASHTO guidelines, and local design manuals depending on your region. The numerical problems in the early chapters are straightforward, but the later chapters on pavement analysis and traffic control require you to understand the underlying assumptions, not just plug numbers into formulas. When you encounter a discrepancy between the textbook value and a code-specified value, trust the code. The book sometimes simplifies for pedagogical reasons, and those simplifications do not hold in detailed design work. The book is good. It is not exhaustive. Treat it accordingly and you will save yourself a lot of time compared to treating it as the final word on highway engineering.
