Achieving Chartered Transport Planning Professional (CTPP) status is a goal for many individuals who have gained extensive knowledge of transport planning. There are, however, potential pitfalls in the process that candidates need to be aware of and, ultimately, avoid, according to Stephen Cragg, Head of Appraisal and Model Development at Transport Scotland.

“I’m a reviewer for the people who are trying to become CTPPs,” explains Cragg. “Candidates looking to become a CTTP will typically submit a portfolio of evidence. They need to demonstrate competency in a range of professional and technical skills.

“The three technical [units] that candidates fail most commonly are: transport appraisal & evaluation, transport model[ling], and forecasting and data.”

Giving insight into transport appraisal techniques, Cragg continues: “As reviewers, we are appraising someone’s ability to do a transport appraisal. It is both extremely simple and extremely difficult to do. That might sound stupid, but one of the problems is that every decision we make is an appraisal.

“This makes humans absolutely brilliant at doing appraisals, but because the vast majority of decisions we make are about ourselves, if we get it wrong, it's only ourselves that get affected by it. But when you're doing public transport appraisal, you're making a decision on behalf of, hundreds, thousands or possibly millions of people.” 

In the CTPP application process, Cragg believes that a candidate’s brains is wired to what they think is the right answer, particularly because most of them will be experts in their field: “Someone might naturally say that the right thing to do would be to build a tram line, but they’ve already jumped through so many of the stages of transport appraisal because we are so good at doing that.”

Two different approaches

There are two approaches to doing a transport appraisal, says Cragg, the first being a top-down view. “Humans are fabulous at thinking we’re all unique – and also that everybody is the same as us, [but they are not],” he explains. “It's an odd paradox, but we are very like that and that’s where, broadly speaking, I would say most people fail to understand the big picture of what transport appraisal is. But once that clicks for you, the rest of it actually tends to fall into place.” 

And then there’s the bottom-up view: “Transport affects thousands of people in lots of different way, so there’s a lot of technical work in trying to understand how something will affect many different areas.”

When it comes to candidates displaying proficiency in doing a transport appraisal, Cragg points to a mosaic analogy. “To demonstrate experience, you need to have made all the individual tiles. Proficiency is the skill of taking all those tiles and creating a picture that makes sense to the reviewers.

“It’s also understanding that no two transport appraisals are ever the same and that you should never compare two as every study area is unique.”

Learn how CIHT can help with getting your CTPP. Get help from reviewers and those who have recently passed.

Transport Appraisal

CIHT has been a consistent and influential voice in debates on how transport appraisal should evolve to better reflect climate, health, place and social outcomes, rather than being dominated by traditional cost–benefit metrics such as journey time savings. CIHT’s position has developed through responses to HM Treasury’s Green Book review, Department for Transport (DfT) appraisal consultations, parliamentary evidence, and sector research.

Read more: Response to the DfT’s Appraisal, Modelling and Evaluation consultation (Oct 2025)

Image: transport planner at work. Credit: Shutterstock.