How to improve the safety of ride sharing by design

Jun Nie


According to the principle of modular design, this paper divides lifting process into six different parts. By comparing the safety measures used by Chinese ride hailing software Didi Chuxing and American Uber in different modules, some suggestions for Didi’s re-launch ride sharing products will be provided.

Key words

Safety Female Sexual-assault Design Social responsibility


As ride-hailing applications become more and more popular, the safety problems of passengers, especially the personal safety of female, have become more and more serious with the repeated exposure of sexual assault cases. Didi in China even had to suspend its hitch service when two women were brutally murdered by drivers after sexual assaulting within three months. Recently, Didi hitch, which added a number of security measures and technologies, resumed trial operations. Faced with these security measures closely related to people’s travel safety, we cannot help wondering how much safe protection these special designs can provide for passengers? And what are the gaps that are not fully covered or connected closely enough? This article will help users have a deeper understanding of the travel products they use every day by sorting out the design principles and safety technologies behind the simple interface, hoping that users can make a better use of them to protect themselves during the ride sharing.

  • Background information

The emergence of ride-hailing software has brought a lot of convenience to our lives, and the emergence of ride-sharing mode has reduced people’s travel costs through resource sharing. Didi is the most popular car-hailing app in China, like Uber in the U.S.

As a largest ride-hailing platform in China, Didi has cornered more than 90 percent of the Chinese market. However, Didi’s rapid rise has also exposed problems and flaws in its product design and business logics, and the lack of safety guarantees for passengers, especially for female, is the most notably. In 2018, an airline stewardess in Zhengzhou was brutally killed while riding a Didi hitch, and within three months, another Wenzhou woman was raped and killed by the driver after repeatedly asking for help in vain on the way. The tragedies made Didi have to suspend the hitch service and reform on the safety issues in its product design and service systems. Meanwhile, Uber Technologies Inc. said it received 5,981 reports of sexual assault during 2017 and 2018, which underscores the risk that has been a chief criticism of ride-hailing companies around the world.

  • Existing problems and practical significance

By analyzing the rape and murder of a girl in Yueqing, Wenzhou, on August 24, 2018, we can find that the flaws in Didi’s product design and service made the perpetrators’ plot easier to succeed. Didi failed to respond to a passenger’s complaint about the driver the day before, so the victim was tortured the next day. The driver’s information was not available to the family until four hours after the incident, because “the information involves the user’s privacy and the front-line customer service staff does not have rights to access”. After the police intervention, they were required to provide an introduction and a police officer’s id for identity verification before they received the license plate number and driver’s information, which delayed the rescue time. These problems exposed huge defects in Didi’s user evaluation and feedback system, customer service system, and the conflicts between user privacy, information security and emergency management system were intensified in an unprecedented way in the emergency. Although the design cannot fundamentally prevent the occurrence of similar tragedies, the optimization of design and a closer connection between each module can greatly improve the safety factor of passengers and decrease the using risks. Therefore, the discussion on this issue is of practical significance.

On Nov 20, 2019, Didi hitch began trial operations in seven Chinese cities after a long and multi-faceted adjustment. This time, Didi provides multiple security measures, such as real-name authentication and face recognition before the formal use of lift service, looking through the new features for safety, authorizing the automatic recording function, learning the basic safety knowledge and completing six safety quiz. Besides, everyone needs to read and check the “Didi hitch travel initiative”, “Lift platform privacy policy”, “Lift information platform user agreement”, etc., and has a free casualty insurance provided by the platform.

These cumbersome procedures seem to temporarily calm users’ anxiety, showing great sincerity in demonstrating Didi’s efforts to ensure passengers’ safety. However, from the user’s perspective, the design principles and technologies behind these security measures remain “black boxes.” Without a deeper understanding of the safety measures used in every part of the ride, it will be difficult for users to fully trust Didi’s hitch service again. Therefore, the whole process of issuing an order to the driver, picking up the passengers and driving according to the course, sending the passengers to their destination, getting payment and evaluation should be divided into different modules supported by various safety methods. What technologies and design principles have been used to ensure the safety of the passengers need more detailed interpretation to the users.

In addition, except for the cumbersome use procedures that have caused some users’ dissatisfaction, the newly launched Didi hitch is controversial because it limits women’s access to rides from 5 a.m. to 8 p.m. Critics say Didi’s adjustment is misplaced, because they know the bad guys cannot be eradicated, getting rid of female users will be more simple. Banning women from using hitch rides late at night and early in the morning seems to reduce the likelihood of female victimization, but it is suspected of discriminating against female and violating the rights of female groups. It is absurd not to provide lift service for women at some period of time for the purpose of safety protection. Its essence is an avoidance of this kind of problem and a helpless action in the trial operation stage. In order to carry out long-term operation smoothly, a more reasonable solution must be found.

Therefore, this article divides the safety problems during the lift into six different modules and makes a specific analysis on the safety measures and technical support required by each part. By comparing the security measures used by Didi and Uber in each section, we can better understand the design logic and practical effect behind these black boxes. Finding the differences between can help them have further improvement and learn from each other. We know that the modular design made it possible to partial optimization, even if some modules are still insufficient, we can improve the whole system performance through targeted adjustment. Besides, effective interaction and connection between modular interface can make using experience become more fluent, and then passengers will gain a more comprehensive security guarantee as well.

  • Safety measures during the process
  1. Driver access qualification screening and review

The first step to effectively ensure passenger’s safety is to verify the identity of registered hitch drivers. The issue concerns what personal information is collected about drivers during the review and how much that information can ensure that drivers meet safety standards.

In the August 2018 incident, an investigation showed that the driver had a number of bad loans. Many tragedies might have been avoided if access to drivers had been strictly monitored at the beginning. In addition to requiring all drivers to upload their id cards, driving licenses and registered vehicle information for re-registration, the newly launched Didi hitch tried to cooperate with third-party credit products, such as the public security organs and list of dishonest persons to conduct comprehensive background checks on registered car owners. All users, including passengers, are required to submit id cards for real-name authentication and face recognition to ensure the authenticity of registration information. At the same time, Didi took the lead in the industry in launching a “video verification function”, which requires that identity information must be collected dynamically in the form of video, in order to prevent identity information fraud and other black industry chain cheating.

“In 2017, Uber kicked off a comprehensive effort across the company to focus on safety.”  When it comes to “strengthen background screenings for drivers”, the background-check process of Uber is very rigorous, and on an ongoing basis. “Although the criteria for background check varies by state, Uber mostly conducts digital background checks via a startup called Checkr.” Checkr screens applicants by using Social Security numbers to identify associated addresses and then reviews driving and criminal histories in national, state and local databases. Every US prospective driver must undergo an annual Motor Vehicle Record (MVR) review and a thorough background check for issues including, but no limited to, driving violations, impaired driving, and violent crime before their first trip. Uber will disqualify individuals with any felony convictions—including sexual assault, sex crimes against children, murder/homicide, terrorism, and kidnapping—at any time in the person’s last 7 years, the potential driver will be disqualified according to Uber’s standards.

Before performing annual background check, Uber was the first US ridesharing company to implement continuous driver screening technology, which monitors and flags new criminal offenses through a number of data sources to make sure that every driver meets the high standard continuously. Both its real-time tracking of crimes and its annual review of driving qualifications have helped Uber screen out a large number of drivers who do not meet the standards because of their criminal records. “During 2017 and 2018, more than one million prospective drive did not make it through Uber’s screening process, and more than 40,000 drivers have been removed from the app due to continuous screening. Therefore, strict access rules and a high-standard elimination system ensure that Uber has a team of reliable and credible qualified drivers to provide safe driving services for passengers.

Therefore, judging from the screening of drivers’ qualification, Didi still needs to carry out specific implementation in many aspects. With a large population and incomplete credit investigation system in China, it is difficult to find a reliable third party for personal information review. In addition, the real-time monitoring of crime data and timely elimination can effectively avoid the loophole between the annual qualification review, and a more detailed screening system can strictly guard against the fluke mentality and criminal behavior. Uber’s dynamic monitoring and continuous examination design are very worthy of Didi’s reference. Regular report of the number of eliminated drivers who do not meet the standard not only make a guarantee of users’ right to know, but also give an effective feedback to the public on driver background check and screenings.

  1. Order delivery and demand matching

Didi hitch is different from taxis and ride-hailing (operating vehicles). The private nature of the vehicles determines the regulatory difficulty. The ride-sharing model based on private cars is different from Uber’s ride sharing service as well. As a non-profit product that aims to make full use of private cars that regularly commute to and from a fixed location to provide convenience for others with the same travel needs. Therefore, whether a driver’s own scheduled trip and a passenger’s destination are on the same way has become an important measure of order delivery.

In the safety overhaul, Didi hitch’s “nearby pickup function” provides four commonly used locations for each car owner, such as the company, home, parents’ home, etc., which can be modified twice every 14 days. Car owners can only pick up passengers between these permanent locations. The setting of common sites can effectively avoid aimless or intentional behavior of choosing orders, reduce security risks to a certain extent. In addition, Didi limits the number of orders one driver could receive every day and sets up a dual confirmation mechanism between passengers and drivers according to local conditions and relevant regulations on private minibus sharing—“the driver is not allowed to choose the passenger while the passenger can choose the driver.” This design principle allows the car owner to invite multiple passengers whose destinations are on the way for ride sharing, and then the passenger can accept one of them or refuse. Passengers can judge whether they are traveling together or not according to the destination, the owner’s trust value and the number of trips. In order to solve the problem of delayed passenger confirmation, Didi has also designed a variety of reminder mechanisms to ensure that passengers deal with the invitation timely.

In addition, in order to provide more security for women who take late-night cars, Didi’s delivery system has made “safety” a precondition since last year, adding “safe order” steps to the previous “global optimal principle”. At present, according to the actual situation of drivers and passengers, the order system of Didi can calculate from passengers’ gender, travel habits, order distance, starting and ending positions, driver’s gender, driving habits, historical order information, complaint records and other more than 200 angles to determine whether the driver and the passenger are suitable.

If female passengers are not familiar with the design principle, they will complain that they have to wait longer than adult men when ordering a car in the middle of the night, because the good drivers with good service quality and low complaint rate may be far away from her. Although this design principle will prolong the waiting time, it can ensure the safety of female late-night travel to some extent. After the company started implementing the “safe order” in September 2018, the number of sex-related crimes committed by Didi in the first half of 2019 dropped by 70 percent compared with the same period last year.

However, the accuracy of “safe order” is limited by the detailed characteristics of both drivers and passengers, and it is difficult for some passengers without real-name registration, new registration or a small number of orders to accurately match the right driver, which will affect the travel safety. In addition, if adult men do not use the “call for other” function when they order car for their female or underage relatives, the system cannot identify the occupant accurately, and therefore the passengers will miss the protection of the “safe order”.

3. Identity verification, monitor and path tracking

When passengers wait for the driver to go to the corresponding location after making the order, the display of personal information and the communication interface of drivers and passengers should be designed specially. At present, both passenger’s and driver’s versions of Didi no longer display specific profile picture and name. The passenger’s mobile phone number will be encrypted, so the driver only can be contacted through a virtual middle number which will expire 30 minutes after the order is paid, and then they will not be able to contact each other again.

Since Didi hitch needs to be booked in advance, the time interval between booking and setting out is long. In order to avoid the change of driver, Didi requires them to conduct face recognition multiple times when they invite passengers with them and when they arrive at the passenger’s starting point. After boarding the car, drivers and passengers can choose whether to use the APP’s recording function to record the journey. These recordings will be uploaded to the platform through real-time encryption, and the recordings without travel disputes will be automatically deleted after 7 days. If someone needs to listen to the recording and restore the scene later, Didi will also request user’s authorization and listen to it in a secure and confidential environment. Similarly, Uber use “Phone number anonymization” and “Real-time identification” to keep passengers’ number private and ensuring the right driver is behind the wheel.

Another safety issue is fatigue driving. While Uber uses “Driving-hours tool” to prevent drowsy driving, which requires drivers to rest for 6 straight hours after a total of 12 hours’ driving, Didi designed a special “Orange video dashcam” to monitor the driver’s driving status at all times. If the driver blinks frequently and slowly in a short period of time, closes his eyes for a long time and opens his mouth to yawn, the recorder will send voice alerts in time and report the situation to Didi’s safety response center via 4G network if necessary.

Besides, all Uber rides are tracked by GPS from start to finish. The “RideCheck” uses sensor and GPS data to detect if a trip goes unusually off-course or a possible crash has occurred. When a potential crash or suspicious trip issue is detected, both the rider and the driver will receive a notification asking if everything is OK. Passengers can share their trip with designated loved ones who can follow their trip on a map in real time and know when they’ve arrived as well. These kinds of real-time monitoring and close connection can bring passengers a sense of security and quickly locate the passengers and vehicles in case of an accident.

4. Emergency rescue

Although both Didi and Uber have adopted a variety of technologies and measures to ensure the safety of passengers, emergency situations are inevitable. How to quickly intervene in the scene to help passengers or drivers, or to quickly locate the vehicle to rescue them after the crime becomes the key to the safety design. Didi requires passengers to set up emergency contacts before use. Once the passenger turns on the “escort mode”, the driving routes of the vehicles will be automatically shared with the emergency contact, and the platform will also pay attention to the track in real time and intervene in case of abnormalities.

In the most urgent situation, Didi’s passengers can choose to call 110 or send a text message to the police. The information of the vehicle, driver and current location will be displayed on the page to facilitate passengers to communicate with the police. Meanwhile, all emergency contacts set up in advance will also receive a text message asking for help. Uber also has a “In-App Emergency Button” in the Safety Toolkit, which can connect riders and drivers directly to 911 with a simple swipe, and the customer support team is specially trained to respond to urgent safety issues, which can provide 24/7 incident support to the passengers and drivers.

Didi outsourced customer service to an unprofessional third-party service platform before, and the front-line customer service had little authority, so they could only give feedback to the superior, which wasted a lot of rescue time in passing information from layer to layer and waiting for feedback. Since last September, Didi has upgraded its customer service capabilities. In order to ensure the professional handling of security incidents, Didi’s customer service system is divided into security system and service system. All complaints related to safety will be immediately transferred to the corresponding security team, a more professional security customer service to deal with. To better assist the police in retrieving evidence in emergency situations, Didi has also set up a 24/7 special docking team. In order to balance the need between protecting personal privacy and police evidence collection, Didi divided user information into three security levels with different retrieval processes, ensuring that 98% of the primary and secondary information could be obtained within 10 minutes. Hoping that these lessons learned from the bitter experience can help Didi make targeted adjustments and improvements, providing reliable assistance and timely rescue to passengers in times of emergency.

5.Passenger feedback and rating system

Since 2016, Didi has evaluated the scores of passengers and car owners through the “trust value”, hoping to encourage users to abide by the rules of the platform and travel in harmony by establishing a credit mechanism similar to the score system for illegal behaviors accumulated by traffic management departments. The “trust value” is designed for both vehicle owners and passengers. It is 12 points initial to measure the reliability of users on the platform. 2, 3 or 5 points will be deducted for the car owner’s lateness, malicious comments, harassment and other behaviors that result in complaints from passengers. For passengers, 2 or 3 points will also be deducted if a driver complains about tardiness and malicious comments. When the “trust value” is lower than 7 points, it will receive a platform warning; when the value is lower than 5 points, user will be banned for a certain period of time; when it encounters a major complaint or the score value is lower than zero twice, the user will be permanently banned.

The recently launched Didi hitch upgraded the “trust value” to a “behavior score” based on a micrometer scale. More behavior, evaluation and complaint data are included in the score, and comprehensive evaluation is conducted from four dimensions: performance, compliance, friendliness and cleanliness. Only those who abide by the agreement, do not cancel the order or be late, obey the rules of the platform, keep vehicle interior clean and tidy, communicate with passengers friendly during the journey can get a higher “behavior score”. Users with high scores will be entitled to the priority of passenger travel display, the priority of driving orders, the priority of new product functions and other rights and interests. Users with lower scores will be subject to stricter restrictions, such as delayed delivery of orders, cancellation of double compensation, and restrictions on receiving orders for special situations. Both drivers and passengers with behavior scores below 400 will no longer be able to use the hitch service.

Uber uses a 2-way rating system to keep both the rider and driver experience safe, comfortable, and enjoyable. Compared with Didi, its scoring system is characterized by screening effective scores among all the ratings with a certain tolerance rate, while passengers’ riding behavior is restricted by the evaluation of drivers. According to the drivers, the overall partner rating is an average of individual rating (from 1-5 stars) provided by riders from 500 or fewer most recent trips. Cancelled trips and unaccepted trip requests will not count toward the overall rating, and those unrelated individual ratings will be automatically removed when applicable. In order to avoid a low rating, the drivers should keep both the inside and outside of the car clean, try not to call riders excessively or right away, wait to begin the trip until asking the rider’s name, ask riders if they have a preferred route and avoid asking for 5 stars. Sometimes things may go wrong, drivers who face the unlucky situations are encouraged to hold a good attitude and focus on the things that can control.

A good rating system can fully mobilize the enthusiasm of drivers, even in adverse circumstances, drivers will not worry too much about the damage to the score, so that the driving service can always maintain a consistent quality. Nevertheless, “Respect is a two-way street, and so is accountability,” Kate Parker, Uber’s head of safety brand and initiatives said. Therefore, drivers have option to give riders a low rating anonymous if they habitually leave their trash behind and disrespect the drivers. On May 28, 2019, Uber announced that “riders with ratings that are ‘significantly below average’ may lose access to the app, part of a rollout of the company’s updated community guidelines, which riders must abide by to continue using the service.”

6. Safety awareness and social responsibility

It is relatively easy to design products or procedures to keep passengers safe, but it is harder to “design” in people’s mind and heart. In order to make passengers more aware of self-protection, build safer communities and create a more harmonious social atmosphere, Didi and Uber need to assume more social responsibilities in terms of safety awareness.

For Didi, the new security quiz and pre-use safe training are a good start, but Uber has already accumulated a lot of experience in this area through its own practices. Firstly, Uber has formulated clear and universally applicable Community Guidelines, which provides drivers and riders with prevention information and education materials. Secondly, Uber offers a number of safety tips to reduce travel risk for passengers. For example, passengers should take a second to double-check the App for driver’s information. Only when the license plate number, the car make and model, the driver’s photo are matched can the passengers hop in.  If everyone can form such a habit before every trip, keep alert at all times, and have a certain self-help common sense, with the help of various technical support and safety measures provided by the APP, the possibility of accidents in the car will be greatly reduced. Besides, Uber is committed to help stop incidents before they happen by partnering with and learning from women’s safety groups, building tools and policies, promoting safety. In specifically, Uber pledged $5 million to women’s safety organization, such as “Futures Without Violence”, “RAINN”, “A Call to Men” through 2022, partnered with the National Sexual Violence Resource Center and the Uber Institute to create a taxonomy which can categorize misconduct and sexual assault incidents, invited law enforcement and 100+ women’s safety and advocacy organizations to help develop the processes and technology.

These measures show that Uber is taking the social responsibility of the enterprise and making contributions to build a safer community by connecting various organizations. As mentioned above, the best product design and thorough security measures cannot eradicate evil. However, the improvement of passengers’ safety awareness, zero tolerance of sexual assault and violence in the society, and the sound post-incident judicial processing process and psychological counseling system can greatly increase the cost of violation, reduce the motivation for crime, and fundamentally avoid the recurrence of the Didi tragedy.

  • Limitations and suggestions

According to the user feedback collected by Didi, many of the complaints come from cumbersome safety measures, excessive restrictions on the car owners of hitch rides and inadequate regulations on passenger behavior. Didi still has a lot to do in the trial operation and nationwide promotion phase, and it is constantly soliciting design schemes and rectification opinions from the public, such as “whether men need the guarantee of relatives and opposite sex friends to drive a hitch”.

Although Didi has used some videos and articles to explain new online security measures and technologies, the interpretation of the design principles is not detailed and transparent enough to reassure people who have been shocked by the incidents before. Tim Berners-Lee, who proposed the Contract for the Web, considers that “we need platforms to open their black boxes and clearly explain how they are minimizing or eliminating risks their products pose to society.” Therefore, Didi still needs to put some efforts in explaining the design principles and operation logics behind the user interface. And “releasing reports” to demonstrate the progress they have made and taking more social responsibilities are good ways to build a good corporate image and restore consumers’ confidence.

In addition, Didi restricts the using time of female passengers during the pilot period from 5 a.m. to 8 p.m., which is contrary to the spirit of the contract and the development trend of the future enterprise, because “Companies must understand that long-term success means building products that are good for society and that people can trust them.” The stopgap measure not only cannot fundamentally solve the problem, but also expose the ubiquitous security concerns still remain. Thus, Didi needs to “tackle the negative (even if unintended) consequences of platform design and explore some better solutions in the coming days.


The tragedy on Didi in 2018 caused widespread concern because of its bad influence, but there are also a lot of incidents and disputes that people don’t know about, which may derive from the design of the platform, the lack of safety measures, and the sinister human nature when there is no outside supervision. This paper disassembles the ride hailing process into different modules, from passengers ordering on the APP to drivers delivering passengers safely, sorting out the security issues involved in each section and the technical support needed to solve the problems, finding out the aspects worth learning from each other and further improving by comparing Didi Chuxing, a Chinese ride-hailing app, with Uber in the U.S.

According to the modular analysis of lifting process mentioned above, we find that there are many similarities between Didi and Uber’s security measures, which also means that the technologies used to increase safety are nothing new. The most different point is how these modules interact with each other, and how to combine them in a more efficient way so that we can provide a comprehensive security protection to every user by design.


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