Guidance

National Travel Survey report on recording of e-scooter trips in the travel diary

Updated 28 August 2024

Exploring factors influencing the recording of e-scooter journeys in the NTS travel diary

Authors: Richard Bull, Sierra Mesplie-Cowan, Sophie Pilley, Debbie Collins

National Centre for Social Research

35 Northampton Square

London EC1V 0AX

020 7250 1866

www.natcen.ac.uk

Prepared for: Department for Transport

Background and methodology

Purpose

The Department for Transport (DfT) has some concerns that e-scooter journeys are being underreported in the National Travel Survey (NTS) travel diary. Specifically, DfT are concerned that under-reporting may occur due to:

• the skewed nature of the responding sample towards older age groups, who are less likely to travel via e-scooter
• participants not thinking of e-scooters as a mode of transport
• participants omitting e-scooter journeys in error whilst trying to follow the existing diary guidance on the recording of short walks
• participants being reluctant to record the use of private e-scooters, as it is technically not legal to ride them on public roads or pavements

An initial desk exercise carried out by the National Centre for Social Research’s (NatCen) Survey Transformation Team looked at whether sampling error may be a potential cause of differences in estimates of e-scooter use between the NTS and other data sources. Findings suggested that sampling error did not appear to be a factor. The desk research also looked at measurement error as a likely cause, with NatCen undertaking analysis to compare grossed up diary estimates of e-scooter use to other DfT data sources. This ‘crude’ analysis suggested that the diary estimates of e-scooter use appeared broadly in line with other estimates of e-scooter use. However, this analysis did not address other DfT concerns. This report sets out findings from a package of work that focused on addressing these other concerns.

Review of the NTS travel diaries

A review of the NTS adult and young person’s travel diaries was undertaken by experienced members of NatCen’s Questionnaire Development and Testing Hub (QDT) using a customised version of the Questionnaire Appraisal System (QAS99). The review considered whether there were any potential issues with the visual design, clarity and wording of the diary recording page and instructions that could lead to under-reporting of e-scooter journeys.

Cogability interviews with E-scooter users

Individual cogability interviews were carried out with 12 adult users of e-scooters living in areas of England where e-scooter rental schemes were running. Cogability testing provides insight into the mental processes used by participants when performing tasks asked of them during the survey process, thus helping researchers understand the problems in performing the task. These methods investigate 4 cognitive stages: how participants understand and interpret survey questions, how they recall information that applies to the question, the judgements they make as to what information to use when formulating their answers, and the response mapping process. Unlike traditional cognitive testing, cogability testing features aspects of usability testing, which is the feature of performing a task within the survey process.

Cogability interviews were undertaken with participants individually. Participants were first asked about their e-scooter use, where they travel to using one, frequency of use and why they rent or use a privately owned e-scooter. They were then asked to record their most recent e-scooter journey in the NTS travel diary whilst thinking aloud. This allowed us to explore how participants thought about travel and journeys, how they attempted to record a recent e-scooter journey in the diary, and to identify any issues that might impact on the recording of e-scooter journeys. Finally, participants were asked for any suggestions on ways the travel diary that might make the recording of e-scooters easier.

Interviewers made notes using a proforma as soon as feasible after the interview had been completed. Notes were analysed using a thematic approach, with themes generated from the data and from survey response theory.  

Recruitment

Participants were recruited by a recruitment specialist, Propeller Research, to a specification provided by NatCen. To be eligible to take part in the study, participants had to have ridden a rented or privately owned e-scooter within the last 6 months. Eligibility was determined from responses to a short screening questionnaire. To maximise the chances of finding participants who had used a rented e-scooter, recruitment was targeted in areas of England that ran rental schemes. An information sheet, which explained the purpose of the research and what it entailed was provided to eligible recruits.

Details collected from screening questionnaire were double-checked at the start of each interview. A confirmation was emailed to each recruit.

Interviews

Interviews were carried out via Zoom. A Zoom link, joining instructions and paper copy of the NTS travel diary were sent ahead of the interview, the latter being sent by post, the former link and instructions sent by email. Participants were asked not to look at the diary ahead of the interview. At the end of each interview, all participants were emailed a code to redeem a £30 e-voucher as a thank you for taking part in the interview.

Participants’ characteristics are shown in Table 1. All participants were in employment, 2 were also in some form of education of training. Most participants lived with a partner or family, with around half having caring responsibilities, as parents.

Table 1 Cogability participants’ characteristics

Participants’ characteristics	Detail	Number with characteristic
Gender	Male	6
Gender	Female	6
Age	18 to 24	3
Age	25 to 34	5
Age	35 and over	4
Highest qualification	A level or above	8
Highest qualification	GCSE or below	4
Ridden a rental E-scooter (in last 6 months)	Yes	9
Ridden a rental E-scooter (in last 6 months)	No	3
Ridden a private E-scooter (in last 6 months)	Yes	8
Ridden a private E-scooter (in last 6 months)	No	4
Location	London	7
Location	Other area of England	5

Discussion with NTS interviewers

We conducted 2 workshops with NTS interviewers, to explore the issues relating to the recording of e-scooters in the NTS diary. Workshops included interviewers with a mix of NTS experience, and where feasible included those who had worked on the digital diary pilot as well as the main NTS. For the second workshop, we specifically targeted interviewers who worked in areas with e-scooter rental programs to maximise the chances of interviewers having encountered NTS respondents who used and may have recorded e-scooter journeys in the NTS diary. Workshops took place online via video conference.

Both workshops explored issues with the recording of travel, focusing on the recording of e-scooter trips. Discussion topics included the role that the interviewer and the diary design play in the recording of e-scooters, any issues survey respondents and or interviewers have with the recording e-scooters, and interviewers’ views on the factors that might affect the reporting of e-scooter use.   

In addition, the second workshop considered the cogability participants’ suggestions for changes to the travel diary that would make it easier to record e-scooter journeys. This involved asking interviewers for their views on whether issues raised resonated with their experience and how practical they thought implementing these changes would be.

Structure of report

The report is organised as follows. The desk review section presents findings from the desk review. The sections on interviews with e-scooter users on travel habits and diary usability are concerned with findings from the cogability testing. NTS interviewer reflections on the recording of e-scooters are contained in the section on discussion with NTS interviewers. Suggestions on the steps that could be taken to reduce risks of under-reporting of e-scooter journeys in the NTS travel diary are presented and discussed in the final section along with a summary.

Desk review

As mentioned in the previous section, the adult and young person travel diaries were reviewed using an abbreviated version of the QAS-99. For each diary, each page of the diary was reviewed – front page, instruction flap, example page, and diary recording page – with the QAS questions considered in relation to the recording of e-scooter journeys. Two experts blind-reviewed the diaries and noted any additional issues not covered by the QAS-99 questions. The 2 reviews were compared, and any differences adjudicated by a third reviewer. Below is a summary of the desk review findings for each section of the diary. All findings relate to both the adult and young person diaries unless otherwise stated.

Diary front cover

It was noted that there is no reference to modes of travel of any type on the front cover of the NTS travel diary. The diary front  cover does not appear particularly engaging, especially for younger people (for example, students) who may be more frequent users of e-scooters. 

Diary instructions flap

There is no reference textually or in the iconography on the instruction flap to e-scooters, either on the front or on the rear notes section.

On the front of the flap, there is the instruction ‘1. We are interested in all types of transport; walks and bike journeys as well as cars and public transport’. There is no reference here to e-scooters, nor in instruction 2 ‘…From column F use a new line for each method of travel you used for each stage of your journey (for example, car, train, bus, walk)’.  This is also the case for note F ‘Use a new line for the method of travel you used at each stage of your journey (for example, car, train, bus, walk)’ and note J ‘Which car or other motor vehicle did you use?’. It is not clear whether e-scooters should be recorded as a motor vehicle.

Diary example pages

There is no mention of or icon illustrating e-scooters in this section of the diary. As noted with the instruction flap (section 2), the instruction for Column F does not reference e-scooters, which may impact on participants deciding whether to include them or not.

Further ambiguity arises regarding whether e-scooters should be recorded in the private vehicle section or the public transport section. Some e-scooters are privately owned, whilst others are rented from businesses that have been approved by city/local councils and where there is a rental cost. Unlike the adult version of the diary, there are no icons to symbolise motor vehicles in the young person diary.

Diary recording pages (days 1 to 7)

There are no instructions relating to the recording of e-scooter use on the diary recording pages. It is clear that all modes of transport should be recorded in column F, but there is no specific reference to e-scooters. 

Parking and fair costs are collected for private motor vehicles and public transport. As noted on the example page (section 2) it is unclear whether e-scooter hire costs should be recorded and if so, in which column. This point also relates to hire bicycles and e-bikes.

Other comments from the desk review

There are recommended minimum ages for using e-scooters and some rental schemes insist on users having a driving license to use them. There may be issues around young people using e-scooters for these reasons and thus not knowing whether they should report them in the diary.

Note G on the diary flap says ‘How far did you travel (Miles)?’ but then gives 300 metres as an example.

Interviews with e-scooter users – Travel habits

How e-scooters fitted into participants’ travel behaviour

Interviews conducted with e-scooter users revealed varying travel habits. Owning or having access to a car was common among the e-scooter users we spoke with. However, participants reported using cars infrequently, as they felt public transport was reasonably good. Those outside of London reported using their car more often when it was convenient to do so than those in London. Some participants owned a bicycle, but only one person described themselves as a regular bike user. Most participants reported walking to their destination if it was convenient. For one participant, this was their preferred method of travel, and they used it as their default mode when planning journeys. When pressed for time or a longer-distance journey, participants considered other forms of transport.

Frequent use of public transport was mentioned by those living in large metropolitan cities such as London and Manchester, being convenient and faster than using private forms of transport. Some participants reported using an e-scooter as part of their commute. Most that did use an e-scooter, used it as part of their journey to or from the train station to their place of work. One participant reported using a rented scooter for most of their commute, walking to and from the scooter rank. Outside of the commute, participants reported using e-scooters for journeys with a leisure purpose. Examples included using e-scooters to do sightseeing in cities, to visit a local wildlife park, and to visit family and friends.

Knowledge of e-scooter rules

All participants reported seeing e-scooters around where they lived, with friends, family, and colleagues using them. The increased popularity of e-scooters since the coronavirus (COVID-19) lockdowns was noted by participants, with some referring to e-scooters enabling them and/ or others to “get out of the house” (Male, 35 plus). One participant (Male, 35 plus) speculated that the popularity of e-scooters during COVID-19 lockdowns reflected a sense of “lawlessness” that developed in his local community at that time. Riders knew the illegality of riding e-scooters on public roads but chose to do so as a gesture of defiance. There were some comments about media coverage of e-scooter riders being typically negative.

Understanding of the rules around the riding e-scooters was mixed. Awareness of the requirement that riders must have a driving licence and that you could not ride while intoxicated was high. Knowledge of other rules was more variable, such as: the geographical areas in which e-scooters could be used and which types of scooters this applied to; and the use of protective clothing such as high-visibility clothing and helmets. Only one participant stated that they used protective clothing when riding an e-scooter. Recognition that there were some differences in rules that applied to private and rented e-scooters was low. Those that did recognise there was a difference generally knew that private scooters were illegal to use on public roads.

Rented e-scooter use

Participants were asked about their experience of using rental e-scooters. Those who rented an e-scooter generally did so by using an app to locate and unlock it. Renting on a ‘pay as you go’ basis, paying for the time spent riding the e-scooter, was common. Regular e-scooter users had a subscription, which discounted their rides. Reasons given for using an e-scooter over other forms of transport by multiple participants were that it was fun or seen as being ‘cool’. One participant mentioned he chose to ride an e-scooter over a cycle as he was a “big kid” (Male, 25 to 34). Another participant suggested that it felt safer than a bicycle as the rider had more control on a scooter.

Problems cited with rented e-scooter were locating them, inadequate maintenance of e-scooters and its impact on their reliability; and finding an e-scooter that is charged. For those that use rented e-scooters in London, they frequently referenced ‘dead-zones’ where the e-scooter would stop working past a certain geographical boundary, and ‘slow-zones’ where the e-scooter would slow at traffic lights and junctions. All participants who experienced a ‘slow-zone’ recognised that this was a safety feature.

Reasons given for not having ever rented an e-scooter were safety (specifically concerns that they can go very fast); reliably being able to find a charged e-scooter when you needed one; preference for other modes of transport; increasing rental cost in comparison to their introduction a few years ago; and the negative public view of e-scooters.

Private e-scooter use

Among those we interviewed, there were self-declared early adopters of e-scooters (pre-COVID-19), opting to use them because they felt e-scooters were more convenient and cost-effective than other modes of transport. Those who purchased an e-scooter during COVID-19 lockdowns did so because it afforded them something to do when recreation activities were limited. Reasons for opting to own an e-scooter rather than renting were convenience; cost (being cheaper over time); and wanting something to do during COVID-19 lockdowns. Participants that rode a borrowed private e-scooter did so out of general interest. They had often experienced riding a rented e-scooter first.

Most private owners did not report having technical issues with their scooter, due to them keeping the scooter in good condition. In terms of other potential problems, only one participant (Male, 35 plus) mentioned an encounter with a police officer whilst using his private e-scooter to ride alongside a canal. The officer informed him that riding the private e-scooter was not allowed, but it was not confiscated. The participant knew this was not allowed but felt it was OK as he was doing no harm to those around him.

General e-scooter use

Typically, e-scooter journeys were made in urban areas, reflecting where participants lived and where research took place. They tended to be short journeys of around 10 to 20 minutes and no more than 30 minutes. Participants suggested this equated to a distance of between 2 to 7 miles. Journeys were typically undertaken when the weather was not adverse (for example, raining) and tended to take place during daylight hours, with some participants indicating that they actively avoided riding after dark. In terms of where they were used, this was on quieter streets by choice, though they were also used on busy roads when there was no other option. An e-scooter might be used for an outbound and return leg of a journey or be used to get to a destination with an alternative mode of transport used for the return journey.

Interviews with e-scooter users – Diary usability

Participants were asked to record the last journey they made using an e-scooter in the travel diary. The cogability interviewer did not provide any instructions or guidance to participants on how to do this, rather participants were left to their own devices. In the NTS, interviewers will provide an explanation of the diary completion task to those household members present. Diary placement happens after the household interview has been completed.

Diary completion behaviour

Variation in diary completion behaviour was observed, reflecting patterns noted in earlier cognitive testing of the NTS travel diary. Some participants read the front cover and then went straight to the diary recording page to start recording their travel. A few participants read the notes immediately when opening the diary, noticing that there was a flap with instructions. One participant said that whilst he noticed the flap and thought the information would be relevant, he was distracted by the example page and decided to move on to the recording task. Views on the diary were generally positive: it looked professional, and people generally liked the colours and fonts.

 Understanding of the diary recording task

Generally, participants understood transport to be the method by which a person moved from A to B. However, there was a difference in what participants classified as transport. This difference was principally concerned with whether walking was included or not, or if transport involved machinery.

All participants agreed that a journey involved getting from A to B. Circular journeys were also considered. However, there was variation in whether participants would record this as one or more journeys. This was related to the purpose of the journey: for example, was it a walk, which involved for example, picking up a pint of milk from the shop enroute, or a specific destination for a specific purpose for example, a journey to the shops to do some shopping. A journey could also be defined as involving a mode of transport, other than walking.

Example page

All participants noticed the examples page. As with the instruction flap, there was variation in whether people read the example page or not, and in how much detail. Some people referred back to it when they got stuck or were uncertain about what columns to complete. One participant reflected on there being no example of an e-scooter journey being included on the example page, and that this added to their uncertainty about whether they should record it or not.

Diary recording page

All participants noted the instructions on the diary recording pages. In the main, participants understood how to complete the diary recording page and made the connection between the column headings and the information in the instruction flap. However, there were queries about what should be included under the public transport ticket column (M) if you were paying via an app. In some cases, participants wrote the name of the app in this section.

In addition, there were queries about whether e-scooters counted as public transport. Factors that contributed to this uncertainty were: the public transport columns (M, N and O) of the diary referring to tickets when the rental scooter had been paid for via an App, and not including the distinction between whether the participant was the driver or passenger. Such uncertainty was linked to participants’ definitions of public and private transport and whether e-scooter journeys were undertaken using a private or rented scooter.

 Entering information

Generally, participants felt confident that they were completing the diary correctly. Participants’ feelings about the diary completion task impacted on their confidence rating. There was an “it’ll do” mentality among some, with others feeling it was a fundamentally straightforward task: “it’s not rocket science” (Male, 25 to 34).

As previously mentioned, there was some confusion about how to categorise e-scooter journeys as either public transport or motor vehicle. In one case the participant said that if they had been taking part in the actual survey, they may have just dropped out at this point due to frustration at this. Several participants completed both the other motor vehicle columns (J,K and L) and public transport columns (M, N and O) within the same journey row. Only one of these participants realised after completing the diary that they should only have completed one or the other or none.

Sensitivity with recording journeys made using a privately owned e-scooter

Participants expressed mixed feelings towards recording e-scooter journeys in the actual survey. Some were unclear about whether they should include these journeys, as there was no mention of e-scooters in the text or iconography in the diary. One participant mentioned that as some of the journeys are technically illegal (private e-scooter journeys on public roads) they would opt not to record them.

Others, however, felt more comfortable. One participant acknowledged that whilst private e-scooter journeys on public roads are illegal he would have been caught on cameras going about his day on an e-scooter. As such, he felt that recording this in a diary would make no difference. Another participant (Male, 35 plus) who was unsure at the legalities of riding an e-scooter felt that he had “nothing to hide”.

There was a feeling that others may not record e-scooter journeys because of the legalities of riding an e-scooter. This indicates that there could be social desirability bias in completion of the diary. On a wider level, when asked about why people may not be recording journeys in general, it was suggested by participants that this could be due to people not wanting to share information with others about their activities.

Summary of findings

Interviews with e-scooter users suggest that e-scooter journeys may not always be recorded in the diary due to the omission of e-scooters from diary instructions and recording pages. However, it should be noted that the reading of instructions was variable. There was uncertainty about how to record information about the cost of using a rental e-scooter in the dairy. There was some, albeit limited evidence, to suggest that private e-scooter journeys may not always be recorded, as their use was known to be illegal and there was concern over negative consequences if use was reported. Participants concepts of what a journey is varied and there was some evidence that short e-scooter journeys may be missed. This may also lead to the under-reporting of short walks.

Suggested changes to the diary

Participants were asked what changes they would suggest are made to the diary. Suggestions raised tended to fit within three main themes: the instructions in the diary, reassurances of confidentiality, and the visuals in the diary.

Participants mentioned that there should be explicit reference to e-scooters in the instructions. Some participants were unclear if they would know to include e-scooter journeys, as there is no direct reference to this form of transport in the diary. Some participants felt that additional information is needed on what to include as public transport. This is not only for e-scooters but also for rental bicycles, including e-bikes. There also needs to be more information about how to record payment of use of rental e-scooters (and bicycles) in the diary, as the current ‘ticket’ option is not appropriate for app payment.

One participant mentioned that there needs to be text reassuring participants that their responses will remain anonymous. He believed that this would reassure participants who use e-scooters illegally to record their journeys. Privacy concerns regarding recording of people’s movements were also expressed, and as such reassurance could encourage accurate recording of journeys.

Participants said that the diary should include an icon or graphic in line with other forms of transport, to ensure that people know to include e-scooters journeys. In terms of immediate visuals, one participant (Female, 18 to 24) felt that the diary “bombards” you with information as soon as you open it, and it should be designed to be more simplistic in more visual content instead of textual. A few felt that the diary was outdated in a paper format and would recommend that it transfers to an app version.

Discussion with NTS interviewers

Interviewers’ experience of the recording of e-scooters in the diary

None of the NTS interviewers we spoke with had encountered survey respondents who had used or recorded an e-scooter journey within the diary recording period, even though the second workshop included only those interviewers working in areas with e-scooter hire schemes (see background and methodology). Some interviewers recalled participants talking about riding an e-scooter on holiday. However, none had encountered situations where they suspected respondents of not recording private e-scooter journeys in the diary, for example, because they saw an e-scooter in or around the respondent’s home, but no e-scooter journeys had been recorded in the diary.

Interviewers in both workshops suggested that the reason the NTS diary was not capturing many e-scooter journeys was because the NTS respondents tend to be older. Interviewers believed that older people unlikely to ride e-scooters: e-scooters tended to be ridden by young people. However, interviewers noted that young people less likely to take part in the NTS, or if they did interviewers typically had no contact with them when placing the diary. This latter point was emphasised by interviewers, because in these situations the interviewer did not have the opportunity to prime the young person to record their e-scooter journeys in the diary.

Interviewers’ understanding of the diary recording rules and their applicability to e-scooter journeys

Two factors mediated interviewers’ decisions in regard to whether an e-scooter journey should be included in the diary or not: the distance of the journey; and whether the journey took place on a public highway.

Journey distance

On asking interviewers about whether e-scooter journeys should be recorded if they were under a mile, interviewers expressed different views. The first view was yes, these journeys should be recorded in the same way as other forms of transport. The second view was no, these journeys should not be included after the first day, in keeping with the recording rule for short walks, which states that walks under a mile should not be recorded on days two to seven. A third view was that it depends on the purpose of the journey; journeys that are for short errands should not be recorded.

Whether the journey takes place on a public highway

Interviewers were also asked about whether private e-scooters should be recorded in the diary. There were different views. Some interviewers felt that e-scooter were like any other form of transport and as such journeys involving their use should be recorded. However, other interviewers believed that private scooter journeys should not be included. This was because they believed that only journeys involving transport on public highways should be recorded, not journeys on private land, including for example “parks”. Applying this rule would exclude the recordings of private e-scooters because they can only be used legally on private land.

On asking interviewers about whether journeys by rented e-scooters should be included, there was a consensus that they should. However, interviewers’ rationale as to why these journeys should be recorded varied, reflecting their beliefs about whether all journeys should be recorded or only those on public highways. Interviewers believing the latter applied the following logic: rental schemes are licenced and as such rental e-scooters can be used legally on public highways, so rental scooter journeys should be included in the diary.   

Such variations in interviewer beliefs about whether all journeys or only those that involve travel on public highways, and whether journeys of more than a mile should always be included suggest that current guidance and training is not sufficiently clear.

Recoding the cost of e-scooter rental in the diary

Users of e-scooters, who took part in the cogability interviews (see background and methodology) identified an issue with the recording of e-scooter rental costs made via an app in the diary. Interviewers were asked about this issue and had mixed views. Some interviewers believed that rental  e-scooters were not public transport, in the same way that a rental car or bicycle was not public transport. Public transport was defined by these interviewers as involving up-front payment  and a pre-defined route and destination. Renting an e-scooter was thought to involve payment at the end of usage and  the freedom to travel to a destination by different routes. This shows the interviewers interpretation of what public transport is different and may influence how they instruct participants to complete the diary.

Interviewer training and guidance on recording of e-scooters in the diary

Interviewers felt they had a good understanding of the rules around the recording of e-scooter journeys, given the guidance they had received. Interviewers remarked that current guidance is adequate, enabling them to help guide respondents on the correct recording of journeys. When probed on e-scooter specific references in training and guidance materials, some interviewers referred to the most recent briefings which included reference to the new CAPI questions. Whilst interviewers rarely came across e-scooter usage, they felt confident that they knew how to guide participants in recording an e-scooter journey, if the occasion arose.   

Summary and next steps

Answers to research questions

This research was concerned with three questions: do participants think of e-scooters as a mode of transport; do participants omit e-scooter journeys in error whilst trying to follow the existing diary guidance on the recording of short walks; and are participants reluctant to record the use of private e-scooters, as it is technically not legal to ride them on public roads/pavements?  These questions are answered below drawing on evidence from the cogability interviews and workshops with NTS interviews.

Answers to research questions: a summary of the research evidence

Do participants think of e-scooters as a mode of transport?

Cogability participants were unanimous in thinking of e-scooters as a mode of transport.

Confusion arose as to whether e-scooters should be recorded as public or private transport (cogability participants and NTS interviewers)

Do participants omit e-scooter journeys in error whilst trying to follow the existing diary guidance on the recording of short walks?

NTS interviewers had not encountered omission of e-scooter journeys when checking diaries, in error or otherwise.

Evidence from the cogability interviews and the workshops with NTS interviewers suggests that the NTS’ rules around what journeys should be recorded (length and whether journey is on a public highway) were interpreted in different ways. With variation in understanding of the rules, there is a risk of under-reporting of e-scooter journeys, particularly those under a mile.

Are participants reluctant to record the use of private e-scooters?

Interviewers had not encountered reluctance in the reporting of journeys made by private e-scooter. However, this should be viewed in the context of interviewers not having encountered any NTS respondents who had used an e-scooter during the diary recording period.

There was some, albeit limited, evidence from the cogability interviews to suggest that private e-scooter journeys may not always be recorded, as their use is known to be illegal and there was some concern about individuals experiencing negative consequences if use was reported in the diary

In addition, the lack of mention of e-scooters in the diary instructions, example page and on the recording page was noted by the desk review, cogability participants and some NTS interviewers.

What interviewers thought of the suggestions made by e-scooter users

Cogability participants were asked what, if any, changes they would make to the travel diary that they thought would be helpful for recording e-scooter journeys. These suggestions were replayed to the NTS interviewers who took part in the second workshops, who were asked to consider them in relations to their practicality, impact on encouraging the recording of e-scooter journeys, and risk of unintended consequences if the change were implemented. Interviewers thoughts on the suggestions are summarised below.

Table 2 Interviewers’ thoughts on cogability participants’ suggested changes to the NTS diary

Cogability participants’ suggestions	NTS interviewer thoughts on suggestions
Adding an icon of an E-scooter to the diary, the most common suggestion	Good idea, but icon needs to be clearly distinguishable as an e-scooter, not a manual scooter . Should all modes of transport have an icon?
Adding an E-scooter journey to the example page	Good idea, but is it necessary?
Focussing on confidentiality due to the illegal nature of private E-scooter use, explaining there would be no repercussions for saying you have used a private E-scooter	Mixed views. Some scepticism about whether this would make any difference unless in print on a DfT branded document . May be more of an issue for younger people
Updating the payment section as E-scooters do not require a ticket, instead you pay using an app	Not encountered this problem. Not public transport as do not buy a ticket/pay for travel up front, as you do with a train or bus
Having a definition of transport which mentions it can include anything that gets you from one place to another and list E-scooter amongst the examples	Could be useful, but is it necessary? There are other forms of transport that are not explicitly mentioned in the diary

Suggested next steps

This research has highlighted some potential reasons why e-scooter journeys may not be recorded in the travel diary, which relate to survey definitions and survey interviewers and respondents’ understanding of these, as well as the design of the NTS diary:

• there are various things that could be done to address these problems
• including reference to e-scooters in the diary instructions might encourage those that read the instructions to include them. The inclusion of an e-scooter icon, if it could be designed in a way that clearly conveyed it was an e-scooter, might also encourage recording
• DfT could consider adopting a broader definition of transport and journey, which might align better with the public’s definition of these concepts. The existing definitions could be used analytically, when reporting, to retain continuity over time. This approach might also lead to improvements in the reporting of short walks. Further work would be needed to map the public’s mental map of what transport and journey are, as this project only involved e-scooter users
• interviewer guidance and training could be reviewed and revised to ensure that interviewers have a consistent and correct understanding of these concepts and how to apply them to the recording of e-scooters

However, when placed in the context of NTS interviewers’ experience, we found no evidence to suggest that under-reporting was actually taking place. None of the interviewers we spoke with had ever encountered someone who had used an e-scooter within the diary recording period. It is therefore not clear if the suggested changes to the diary, shown in table 2, would have any impact on improving NTS diary estimates of e-scooter use: indeed, there is a risk that changes may have unanticipated, negative impacts. Further development work and trialling of proposed changes would be required to determine their impact.

Given the lack of evidence that supports the hypotheses that the discrepancy between administrative and NTS data on e-scooter is due to response bias and or measurement error, we suggest there might be an alternative explanation. There are a limited number of e-scooter rental schemes in England currently, and e-scooter use tends to be concentrated in urban areas. The NTS is design to provide national estimates of transport use. It might be that the NTS sample design does not sample enough e-scooter users because the sample size is not large enough to pick up this travel behaviour in areas where there is likely to be use. As a result, the NTS appears to under-report e-scooter use. This hypothesis could be explored further.