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Car Rental Booking Process Analysis

Analysing the booking forms for 32 Car Hire companies

Created by Al Mackin

Why analyse booking processes?

Booking a car can be a long process with lots of options and questions. Before the potential customer enters their personal information they have to decide what type of car they want, where they want to pick it up and drop it off, and the date and times for both start and end. Combined with the personal information required at the end of the process, this means a lot of fields, and a lot of thought.

The challenge for car hire websites is that users want to get through the process as quickly as possible - they may be excited about having a hire car at the end of the form, but they want to spend as little time as possible entering information in as possible. This puts pressure on the provider to have a short process, and also an easily understood process. When users rush through forms, they don't pay attention to the instructions.


Analysing the booking process for car hire websites was an interesting research piece for me. There's a significant difference between the easiest and hardest forms to complete, and if you're in this industry then my research and commentary will help you optimise your process to maximise conversion rates.

Jump to the league table for all Car Hire companies

Customers dislike filling in forms. If a form is too long, too complex or can't be easily understood then this leads to:
Higher CPA Increased Abandonment Higher Marketing CPAs

Analysis Overview

I carried out this analysis in March 2018 and started by creating a persona to use across all the websites. This means that the information I entered in the booking process was standardised.

In my analysis I counted only the required fields, so optional fields were noted but not included in my numbers.

Finally, when an "average number" is noted in this report it is a median average unless stated otherwise.

  • I analyzed and tested 32 Car Hire companies

    I reviewed the booking form for almost every major Car Hire company

  • 52 metrics are used to measure performance

    My research is focused on every aspect of the form, from the form elements to the timing and mobile usability.

  • I ranked and rated each process

    I scored each form based on critical factors that will increase user frustration and decrease conversions

Four Key Take-aways

43.8% of companies have no address lookup fuctionality. A basic or automatic address lookup allows the user to type only part of their address and then looks up the remainder of it. Reducing five fields, to just two (on a basic lookup) or one (on an automatic lookup) will have a significant impact on conversion rates.


68% of sites do not explain more complex or personal fields. Users can get thrown by fields that are non-standard (like, say, driving license number, mobile phone number) and an explanation will help them understand why you're asking for that information. The less concern they have about completing your process, then the more likely they are to complete it.


Only 34% of sites use inline validation on success and failure. Showing error messages to users as they move through the fields will allow them to fix issues quickly, and they can do so whilst their mind is on that particular field. The opposite of inline validation is submit validation, where all of the fields are checked at the end of the process, and then multiple error messages may be displayed. Going beyond validating inline for errors, is validating for success. Adding a green tick, or making the border of the input element green, confirms to the user that they have successfully completed the field, giving them confidence to move through the rest of the fields.


53% of sites do not use mobile keyboards on phone number fields. Showing a mobile-friendly keyboard, in this case a number keyboard, will make data entry significantly easier, and is a relatively easy optimisation. Making sure that your site uses the mobile, telephone and number keyboard types will allow the growing number of mobile users to get through your forms faster. 41% of sites do not use the email mobile keyboard.

Analysing the Booking Process for Car Hire websites

Each step or block in a booking process is a new area for a potential customer to read and absorb. Whilst there is no magic number of steps that will lead to a higher conversion rate, having too many steps will likely decrease conversions, and having illogical steps will confuse the user, and likely increase the time to complete the process.

The median number of steps across all car rental forms is 2.

If you have more than one page, or step, in your process then it's important that you show the user how far they have progressed. In a single step process the user can see all the fields, and therefore have a gut feel of the effort required (this can cause people to abandon a process on the first step if it just looks too long). When a process has more than one step, there is an unknown amount of effort required to complete all the steps. Showing the user that they are on Step X of Y is one way to help them understand that this is (ideally) a simple process, and that they are Z% of the way through it.

Having a visual indicator of progress through steps is an easy, but important, way to help users understand how close they are to completion.

The fewer fields, the greater the chance of conversion

Users fundamentally dislike completing forms, they want to complete the booking process as quickly as possible. The fewer fields that the user has to complete, the less frustrated they will be, and the more likely they are to transact with you.

Whereas the relationship between the number of steps (see the block above) and the conversion rate is often indirect, there is a strong relationship between the number of fields and conversion rates. A potential customer who sees a shorter form is more likely to complete it, and the time required to complete a shorter form is less. Aggressively reducing the size of the form, and reducing the effort required to complete it, will have a positive impact on conversion rates.

The average number of fields across all the car hire processes is 20.

In my research I found the longest form was Sunny Cars with 31 fields, 50% more fields than the median. Orbitz and Travelocity have just 9 fields to complete. The difference in effort, and time, is significant. It is highly likely that those sites will see a stronger conversion rate than Sunny Cars.

Top or Back-loading a booking process?

Should you ask more questions in the first step or the last step? Should we ease our customers in on Step 1, or let them get through the bulk of it? Or should we have just a single step with all our fields in it? These are common questions when thinking about how your split a process into multiple steps.

The question over top-loading (or not) is an important one. Ask too many questions in the first step and the user will be put off, whilst having too many steps will make the user believe that they're engaging in a virtually endless process. It is important to show to the user how far they are in a process, and how many steps are left.

Across all car hire booking companies 56.2% of sites have two steps. 87.5% of sites have three steps or less.

If you're looking to optimise your conversion rate by adjusting the number of steps in your process then a sensible starting point for testing is the average across all companies: 36.3% of fields are shown in the first step, with 46.5% in Step 2, 11.8% in Step 3 and 4% in Step 4.

Extra Steps in Car Hire Forms

The graph below shows the number of steps in a car hire process that don't have standard input elements. This includes the process of choosing a car, and optional steps that don't have a form.

Some Process are significantly longer than others

The main factor in a form completion time is the number of fields, with a trend of a lower completion time when there are fewer fields. A secondary factor in time to complete is the type of fields used: text inputs take up the most time, followed by drop-downs, then radio buttons and finally tick boxes. Radio buttons take an average of 2.8 seconds to complete (from absorbing the question, to selecting the answer) compared to 3.6 seconds for drop-downs. Not only does a higher number of fields mean more time required to enter data in each field, but it also takes time between the fields as the user completes one question, moves to the next one, absorbs what is required and then start to complete it.

Reducing the time to complete will decrease the window for a user to abandon, the period between them entering the booking process and completion. Even small adjustments to the labelling, explanations, validation and the form fields themselves, can cut down the time to complete. When you have a high volume of customers transacting each day that reduction will lead to a higher conversion rate, and increased revenue.

On average it takes a customer 98.65 seconds to complete a car hire booking form.

National has the highest time per field (the total completion time divided by the number of fields) at 5.33 seconds, with Interrent having the lowest time per field of 4.45 seconds. However National has a third fewer fields than Interrent (10 vs 29). Avis, Europcar, Hotwire and Sixt are four well known brands that sit within the top ten most time consuming processes. Avis takes 133 seconds to complete, Europcar 122.3 seconds, Hotwire 117 seconds and Sixt 113.5 seconds.

Comparing Priceline and Hertz shows the importance of using fields that are faster to complete. Hertz has two fields more than Priceline (22 vs 20) but actually takes one second less to complete. Hertz also has a much lower average field time (4.59s vs 5.10s) driven by using less text boxes, and more drop downs and check boxes, than Priceline.

Why Radio Buttons save time

Radio buttons trump Drop-downs for two reasons. Firstly all of the potential options are visible and readable by the user on a radio button. A drop-down requires the user to click and then read the options.

Secondly, the user has less total interaction with a radio button than a drop-down, a drop-down requires a minimum of two clicks versus the single click for a radio. With a form that has a significant number of fields then saving the user fractions of a second will add up to a good time saving, and a greater likelihood of conversion.


Engagement examples: radio vs drop-down


From our aggregated timing data on forms (Formisimo tracks engagement with fields with millisecond accuracy) I can see that the time spent on a radio button (taken from the time of the interaction with the last field to the first engagement with the next field) is 2.8 seconds, whereas a drop-down is 3.6 seconds.




Which field types are used?

The field types used in a form can make a significant difference to the time required to complete it, and the frustration that a user feels.

There are three field types that should be considered when you want to optimise your form by changing the input type: radio buttons, drop-downs and tick boxes. In certain scenarios you can change the field type from one to another, with the aim of making it faster for the user to understand the question and all potential answers, and faster to select the right option.

You can see in the graph below that Rentalcars.com has the lowest proportional usage of text boxes, and the highest proportion of drop downs. The latter field type is faster to complete, and closed, whereas a text box requires the use of the keyboard and more thought from the user. National has almost all fields as text boxes, requiring more typing and thought to complete their process.

Field Types: Highest Performing Sites vs Lowest

Comparing the top five booking processes (ranked using our scoring at the base of the page) and the bottom five you can see how the higher performing sites use a greater proportion of text boxes.

Comparing the UX of a text box (open, requires typing), drop-downs (closed list, requires clicking and reviewing) and radio buttons (closed, all options visible) the radio button wins on total interaction required, and is therefore faster to complete. A radio button requires a single click on the right option, whereas a drop-down requires a minimum of two clicks, with an unfurling of the options. That list will then need to be read and absorbed after the first click, taking up more user time.

Mobile Friendly Forms

The experience of a mobile user is fundamentally different to that of a desktop user. Beyond the way that a form is presented on screen there's a second challenge of how the user enters data, and dealing with the complexity of data entry compared to entering information on a desktop. Making the process as quick as possible is critical for mobile users, as they are more likely to be on the move and have time constraints.

Only 47% of processes use the telephone (or number) keyboard type, with 59% of sites using the email keyboard type.

The use of keyboard types on mobile devices makes it easier for potential customers to complete a form as it shows them the most relevant keyboard for the data input. As an example, a number or telephone number field should show just the number keypad, rather than the full keyboard. A field that asks for an email address can show a keyboard that makes the "@" symbol visible without having to press the shift key. Adding this functionality to a field is relatively easy, and it generally has a positive impact on conversion rates.

Inline Validation key to conversion uplift

Inline validation is a good way to highlight issues as a user moves through a form, allowing potential customers to correct issues before the end of the process.

The more questions, and the more complex the questions, the greater the likelihood that a user will make a mistake. Informing that user of errors as they go through the process is far better than informing the customer of many issues at the end of the process.

Inline validation can also be used to highlight success as well as failure. Typically a green tick is shown next to the field, or a green border is shown on the field itself, to validate to the user that they have successfully completed that field. This constant reminder that the user has succeeded will give them confidence, and make them feel positive about their progress through the form.

My research showed that 12.5% of sites have no inline validation, with 53.1% reporting just on error. 34.4% validate on both errors, and success.

Validating for both success and failure will give the user the best level of feedback as they move through the form, and it gives you the best opportunity of converting them into customers.

Gamifying Long Forms

Website visitors have all experienced frustrating forms and when they start to engage with yours they are carrying baggage from the times when a form has been annoying.

A good way to keep users motivated, and to challenge their belief that the experience will be painful, is to use positive validation as they enter data. This is often in the form of a tick box next to a field and is shown as they exit the field and move to the next one. This positive validation keeps the user happy and helps them believe that when they click the "submit" or "next" button that they will be successful.

Showing errors in-line is equally important, as the user doesn't have to wait until the end of the step to see if they have made mistakes. A good inline validation process will not only show the user if they have entered incorrect information in a field (and so so as they move out of the field) but it will also explain what they need to do to correct it.

Example of Inline Validation


An example of insurer AXA using full inline validation. They highlight when information is correct and also when a user makes a mistake (along with a full explanation of what the mistake is). In the image above I have left the postcode field blank, and then moved to the next field.

Increasing Comfort by Including Contact Details

Adding customer service information to a form gives users the confidence that if they have an issue then they can contact you directly. They're unlikely to need to have a conversation, although some may have issues that you can help them with and that's a useful source of information to aid form optimisation. By displaying phone numbers, an email address or a livechat link, this increases the likelihood that a user will trust your brand, and convert.

9.4% of sites have their contact details visible during the booking process, with 15.6% showing a livechat. 75% of sites have no contact details at all.

Mark required fields

Marking which fields a user has to complete will save them time. It guides them to which fields you absolutely have to enter information into, and which fields you can ignore (there's a question over whether you should have any optional fields in your process). A simple asterisk or similar notation will help the user understand how they can fast-track the process.

My analysis shows that 62.5% of sites mark required fields, with 37.5% leaving them un-marked. For over a third of sites marking required fields is a quick and easy optimisation.

Explaining why you ask for non-standard information

Customers get used to entering certain information into forms: they frequently enter their name and their email address. When you ask a user to enter non-standard information this will slow the process down, as the user will think "Why do you need this information, and should I enter it and continue with the process?".

Explaining why you need this information can reduce the confusion that users have. So, for example, saying "We need your mobile number so we can alert you to any changes to your car hire" will remove the user's concerns about having over their mobile number.

68.8% of sites do not offer an explanation for any non-standard fields. 28.1% have a popup that appears with an explanation, whilst 3.1% have an explanation that is inline (shown next to the field) or hidden until the user clicks on an item.

Using Explanations To Increase Conversions

Forms on car booking processes ask personal questions. Users are cautious, and sometimes confused, about questions that are non-standard. In your day to day life of completing forms this information is rarely asked for, so it can make a user consider why you need that, and then potentially decide to abandon the process.

When your process requires this information then offering an explanation as to why you need it, and what you use it for, is an important optimisation.

There are diverse ways that you can explain to the user why you need this information from them. Showing text around a field is an effective way to make sure that your explanation is always visible, but using an inline popup (that displays the message on the current field, as the user moves into it) is a good way to make the message highly visible.

Example of Field-Level Explanations

American Express have a popup message on some of their fields, and it is currently visible on the email, "Name on Card" and mothers maiden name fields.

The messages are either to confirm why they need that information (in the case of Mothers Maiden Name they explain that this is needed for security and verification) or an explanation of something that may simply confuse the user ("Name on Card" is explained as it can differ from the regular name of the customer).



video showing popups that explain what a field is in a form

Shrink your address fields from five to one

Entering your address into a form is a painful process for users, especially on a mobile device. The number of fields that have to be completed, and the combination of letters, and numbers (and the required switches between mobile keyboards) mean that this takes up a significant proportion of the total time to complete.

Using postcode lookup functionality can reduce the required fields from around five to just two (house number and postcode). This is a significant reduction in fields. Using an advanced, automatic postcode lookup (where the user types any element of their address into a single text box) reduces the form size further.

53.1% of sites do not ask for an address during the booking process, 43.8% have no address lookup and just 3.1% use a standard lookup. That's a very low proportion of sites that use the second best option (standard lookup) and no sites that use an advanced lookup.

Scoring All Companies

To rank each organisation I generated a score out of 76, which took into account the number of steps and fields (related to the median score for each) and scored companies based on the percentage they were above or below this. I also scored companies based on the removal of unnecessary obstacles, and the mobile friendliness of each form based on the usage of mobile keyboard attributes. Having a livechat and postcode lookup was also part of the scoring process, and using inline validation boosted scores further, along with other form features that I considered to be critical to conversion rates.

The aim of our scoring was to take into account attributes of the form rather than the look and feel. Some forms were more attractive than others, but as design is subjective I chose not to apply any marks for forms that I felt looked better or worse.

Get a full league table of Car Hire companies with deeper scoring data, plus read about the methodology behind my scoring, by entering your details:

league table of all Car Hire companies

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