Introduction

Climate change has become one of the toughest social challenges that global sustainable development faces. In 2015, the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) adopted the Paris Agreement in Paris, France, and set the goal of keeping the global average temperature rise in this century within 2 °C and ideally within 1.5 °C (IPCC 2018). To this end, all countries and industries must take measures to control greenhouse gas emissions, including carbon dioxide (CO2).

There has been a growing interest in the relationship between climate change and transportation (Schwanen et al. 2011). Among all the global greenhouse gas emissions, the transportation sector is one of the most significant contributors to greenhouse gas emissions, and its emissions are second only to the energy sector and the industrial sector (Guan et al. 2021; Zeng and He 2023). According to industry statistics, emissions from the global transportation industry accounted for 15.9% of total emissions in 2016 (World Resources Institute 2020). According to the “Climate Change 2022: Mitigation of Climate Change” report published by the United Nations Intergovernmental Panel on Climate Change (IPCC), the transportation sector experienced a stabilization in carbon emission growth rate at ~2% between 2010 to 2019 (IPCC 2018). However, it is concerning that emissions from the transportation industry are increasing at a faster pace compared to other sectors, and they are projected to double by 2050 (IPCC 2022). Transportation had the highest annual growth rates of both energy use and greenhouse gas emissions in China (Du et al. 2017). However, there was an “awareness–behavior gap” whereby low-carbon awareness had a slight moderating effect on purchasing behavior via psychological factors, and government policies had a significant positive impact on the adoption of new energy vehicles (Du et al. 2018). Many cities had introduced Green City Transportation Projects to form a sustainable urban transportation network to meet people’s increasing travel needs, and to promote the development of urban social environment and social economy, reduce the pressure on transportation and reduce the degree of environmental pollution (Tran et al. 2020; Rehman et al. 2023).

Urban transport is an essential part of the transportation sector and is closely related to the lives of urban residents; at the same time, urban transport energy conservation and carbon emission reduction must continue. The global network of cities C40 reported that the share of public transport in cities worldwide must be doubled, and the transition to zero-emission public transport must be achieved by 2030 (C40 2021). Without this transition, countries will not be able to meet the urgent goal of halving emissions by 2030 to have a chance of limiting global temperature rise to 1.5 °C by the end of the century, and transport may remain a roadblock to the world’s efforts to mitigate climate change (Creutzig et al. 2015).

China is implementing a national strategy to actively combat climate change, which has been crucial for promoting global climate policy. On September 22, 2020, in the General Debate of the 75th United Nations General Assembly, President XI Jinping announced “China’s Commitment” to the world: “China will increase its nationally determined contribution, adopt more effective policies and measures, seek to achieve CO2 emissions reduction by 2030, and strive to become carbon neutral by 2060.” Peak CO2 and CO2 neutrality (hereafter referred to as “dual carbon goals”) have been integrated into the overall framework of China’s ecological civilization construction and have become critical national strategies.

The transportation sector is an important area of energy consumption and CO2 emissions, and its contribution to air pollution cannot be overlooked. With the rapid development of urbanization, the proportion of carbon emissions in China’s transport sector has increased yearly. In 2005, transportation accounted for 7.3% of the total emissions. In 2014, the percentage stood at 8.6%, which increased to 9.4% in 2018. Projections indicate that by 2030, it is expected to reach 9.8% (The Economic Observer 2020). This figure underscores the significant distance that needs to be covered in terms of energy conservation, emission reduction, and carbon reduction in the transportation sector, and green transportation has great significance (Lee et al. 2017). The transportation sector has emerged as a pivotal focus area for China’s carbon emissions reduction efforts (C40 2021; Guan et al. 2021).

Literature review

Although moderate energy efficiency improvements have been realized in the transportation sector, global greenhouse gas emissions from this sector have increased from 4.8 to 8.5 Gt CO2eq between 1990 and 2018. Road transportation (including passenger and freight modes) accounted for 73% of these emissions (Lamb et al. 2021). The deployment of low- or zero-emission technologies, achieving emissions reductions in the passenger transportation sector remains challenging (Milovanoff et al. 2020; Raugei et al. 2021). Demand-side mechanisms can be instrumental in reducing environmental impacts of transportation and reconfiguring transportation systems in a way that shifts users away from private car ownership (Velez et al. 2023). Countries such as China also experience a dramatic growth in car ownership, witnessing increases of 400% between 2009 and 2021 (Statista 2023). These trends and current forecasts of car ownership mean it is urgent to have transportation alternatives to private car ownership. We need demand-side mechanisms to support technological progress if we are to successfully transform transportation systems and reduce environmental impacts from passenger vehicles. Such demand-side strategies require an understanding of demand patterns in specific contexts: for example, encouraging changes in lifestyles and travel behavior, transformations of housing patterns, and support for teleworking (Creutzig et al. 2018, Ivanova et al. 2020).

Green transportation

Green transportation is a modern concept based on sustainability and environmental protection with realistic goals to be achieved (Shah et al. 2021). The development of green transportation is mainly based on the basic principles of ecological concept and environmental protection consciousness (Ahmed and Monem 2020). Green low-carbon action in transportation is one of the ten key tasks of Carbon Peaking in China (Zhang and Zeng 2013; Yu et al. 2015). The Carbon Peaking Action Plan before 2030 issued by the State Council (The State Council of the People’s Republic of China 2021) proposes to promote the low-carbon transformation of transportation tools and equipment, build a green and efficient transportation system, accelerate the construction of green transportation infrastructure, and speed up the formation of green and low-carbon transportation modes in the field of transportation (He et al. 2022).

When the public transportation scale exceeded a threshold value, it was shown that the relationship between public transportation and carbon emissions would turn positive to negative in China (Jiang et al. 2019). Green transportation could also reduce other pollutants such as PM2.5 (Shan et al. 2023). In October 2019, the National Development and Reform Commission (NDRC) issued the Overall Action Plan for Green Life to facilitate green life actions in the whole society, to advocate a simple, moderate, green, and low-carbon lifestyle, and carry out various actions, including green transportation actions (National Development and Reform Commission 2019). Following the principle of promoting systematically, participating extensively, highlighting key points, and facilitating based on different categories, in July 2020, the Ministry of Transportation (MOT) and the NDRC jointly issued the Action Plan for Green Transportation (Ministry of Transportation and National Development and Reform Commission 2020). This plan stipulates that municipalities directly under the Central Government, provincial capital cities, cities under separate state planning, cities promoting public transport, and other cities with a population over one million are the objects to promote green transportation. Through promoting green transportation, a simple, moderate, green, and low-carbon lifestyle should be advocated, and the public should be guided to choose green transportation modes such as public transit, walking, and bicycles, reduce the total traffic of cars, and improve the overall level of green transportation in the cities of China. The Action Plan proposes that by 2022, the green transportation ratio in over 60% of the cities promoting green transportation should be around 70%. So far, more than 20 provinces and 109 cities across the country have submitted applications for comprehensive green transport promotion. Shenzhen, for example, has decided that “by 2025, the proportion of green transportation should reach 81%,” and this objective has been incorporated into their overarching goal of promoting, guiding, and implementing green transportation initiatives. Furthermore, Shenzhen aims to prioritize the development of public transportation by establishing an urban mass transit system centered around commuter rail, complemented by conventional public transportation services.

Digital technology and climate mitigation

Digitalization holds one of the main elements in driving change: access to information. Access to transportation information and how it is presented to users influences how they chose to travel (Anagnostopoulou et al. 2020). Research shows that transportation users who receive information about the environmental impacts of transportation modes are likely to change their travel behavior (Franssens et al. 2021). Digital technology refers to a new generation of information technology, including the Internet, Big Data, cloud computing, and blockchain, among others, that can increase production efficiency and reduce carbon emissions. Digital technology can be applied to various fields of economy and society and plays a positive role in promoting green technological innovation, improving economic efficiency, saving energy, reducing carbon emissions, and promoting the green transition of the economy (Balsa-Barreiro et al. 2023). The Exponential Climate Action Roadmap released by Future Earth at the 2019 Global Climate Action Summit shows that applying digital technologies in various fields can help reduce global carbon emissions by 15%–20% (People’s Daily 2022). According to a 2016 Global e-Sustainability Initiative (GeSI) report, digital solutions have enormous potential to reduce greenhouse gas emissions. By 2030, digital solutions such as smart manufacturing, smart agriculture, smart buildings, smart mobility, and smart energy can save over 12 gigatons of CO2 equivalent in the global economy, or about one-fifth of total global emissions (GeSI 2020).

Map navigation, digital tools for public transport and green transportation

The latest data shows that about 250 million people in China travel by public transit daily; 29 cities across the country have operated subway transit, and the annual ridership of public transit across the country exceeds 90 billion person-trips (China Business News 2017). AutoNavi Maps, Tencent Maps, and others started offering “real-time transit services” many years ago. Tencent introduced “transportation codes” in 2017 to facilitate the purchase of tickets. In 2021, Tencent Maps launched a “green transportation portal” to integrate all the functions of public transportation through the “integration of map and code” and continuously optimize the experience of “green” transportation such as traffic code scanning, information inquiry, route planning, walking, and cycling. This is the first time among digital map products that the whole green transportation scenario has been integrated at the strategic level, and the promotion of green transportation has been elevated to the strategic goal of digital map products. In just a few years, Tencent Maps Ride Code has covered over 180 cities nationwide, with over 200 million users.

Based on the literature review, we propose the following research hypotheses:

Hypothesis 1 (H1): More people understand and accept the concept of green transportation and urban travelers prefer green and low-carbon transportation.

Hypothesis 2 (H2): Digital tools such as mobile navigation applications provide innovative and interesting options for public participation in green mobility, increase public’s willingness to use green transportation.

Hypothesis 3 (H3): Effective incentive mechanisms such as Carbon Inclusion Policy will further enhance the public’s willingness for green travels.

Methods

Questionnaire survey on public green transportation behaviors

To understand the public’s willingness to green travel and the role of digital tools in green transportation, we conducted a survey on public green travel behavior. By distributing questionnaires, the current situation and awareness of green transportation among the public were understood. This questionnaire was randomly distributed by Tencent Horizon to cell phone netizens in 31 provinces, autonomous regions, and municipalities according to the approximate China Internet Network Information Center (CNNIC) netizen structure, obtaining 7369 valid samples (see Supplementary Table 1 for the detailed proportions of respondents in different provinces). The survey sample exceeds the minimum size required under 95% confidence and 3% error rate, which meets statistical validity requirements (Perez and Esteve 2007). The sample is statistically representative, and the research results drawn from the survey data can also be applied to all Chinese netizens. Of the respondents who completed the questionnaire, 51% were male, 49% were female, and most were young: 70% of the questionnaires were filled out by young netizens aged 39 and under. Netizens in Shenzhen, Guangdong Province, were the most active participants in the online survey (see the appendix for the questionnaire).

Digital maps assist low-carbon public transport: a case study in Shenzhen

To learn whether the mobile navigation applications could assist green and low-carbon transportation in major cities, we chose Shenzhen as a pilot case, where Tencent Maps’ Green Transportation Portal provides users with transportation services, including subways, buses, walking, bicycles, and shared bike scenarios. Shenzhen is the fourth largest first-tier-city after Shanghai, Beijing, and Guangzhou with a population of 17.66 million. The level of public transportation in Shenzhen represents the current situation of most large cities in China (Chen et al. 2023). Based on the principle of voluntary emission reduction methodology and regarding the relevant parameters of the Shenzhen Carbon Inclusive Methodology for Low-Carbon Public Transportation, we only calculated the carbon emission reduction of Shenzhen users who take subway and bus trips by scanning codes of Tencent Map products (Shenzhen Government 2021).

The calculation adheres to the established principles of the United Nations Clean Development Mechanism (CDM), China’s certified voluntary emission reduction programs, and other emission reduction mechanisms (Zhou et al. 2019). The carbon emission reduction is determined using the following formula:

$${\rm{ER}}={\rm{BE}}-{\rm{PE}}$$

ER is the emission reduction (kgCO2e), BE is the baseline emissions (i.e., GHG emissions generated by the most probable modes of transportation that are being replaced by bus and subway trips). These baseline emissions serve as the baseline scenario (kgCO2e), PE is the project emission (i.e., GHG emissions from bus and subway trips) (kgCO2e).

$${\rm{BE}}=\sum {{\rm{AD}}}_{{{i}}}\times {{\rm{EF}}}_{{{i}}}$$

AD is the trip mileage activity level data for mode i (P km, person-kilometer) and EF is the emission factors of mode i (kg CO2e/P km).

$${\rm{PE}}=\sum {{\rm{AD}}}_{{{i}}}\times {{\rm{EF}}}_{{{i}}}$$

AD is the trip mileage activity level data for mode i (P km, person-kilometer) and EF is the emission factor for mode i (kgCO2e/P km).

Using 3-year Green Transportation Big Data from 2019 to 2021, sourced from Tencent, an estimation was made regarding the total mileage of Shenzhen residents taking the subway through the green transportation platform of the Tencent Map. The total mileage recorded during this period amounted to 25,841,178,916 P km. Simultaneously, the urban traffic transportation emission factor of 0.0812 kgCO2/P km, a per capita subway emission factor of 0.0345 kgCO2/P km, and an emission factor of 0.0543 kgCO2/P km for Shenzhen’s electric buses, provided by the Shenzhen Carbon-Inclusive Methodology for Low-Carbon Public Transportation, were applied to calculate both the baseline and project emissions (Shenzhen Government 2021).

Based on the Green Transportation Big Data provided by Tencent, the cumulative bus mileage of Shenzhen residents utilizing the Tencent Map Bus Code in Shenzhen, specifically from January 2021 to May 2022, through Tencent Map Green Transportation Platform, amounts to 1,000,568,937 P km.

Results

Questionnaire survey on public green transportation behaviors

The main findings of our analysis of the questionnaires are as follows:

Finding 1: the proportion of urban public transport trips is increasing, and over 50% of respondents are considering using public transportation to replace driving private cars

The survey revealed that public transit was the preferred mode of transportation for half of the respondents (50.6%), with walking (43.0%), electric bikes (39.5%), and bicycles (37.1%) following closely behind. Motorcycle transportation had the lowest percentage of users at 10.7%. The overall percentage of respondents who chose to use their car was 32.0%. Notably, when considering respondents who utilized public transportation alongside walking or biking, public transportation accounted for over 50% of the overall respondents. In contrast, private cars, taxis, and online car rentals accounted for less than 50% (refer to Fig. 1).

Fig. 1: Public transit was the preferred mode of transportation for over half of the respondents, with walking, electric bikes, and bicycles also popular.
Fig. 1: Public transit was the preferred mode of transportation for over half of the respondents, with walking, electric bikes, and bicycles also popular.
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The green bar and the percentage number displayed the proportion of choices made by the respondents (multiple choices).

Among them, we analyzed the feedback questionnaires from Shenzhen and found that 93% of the respondents would use public transit as their daily commuting means, whereas 31% and 20% would walk and cycle, respectively. The proportion of private car transportation was relatively low, only 10%, while the proportion of taxi and online car-hailing trips was 16% (refer to Fig. 2 for details).

Fig. 2: Daily commuting modes of respondents in Shenzhen.
Fig. 2: Daily commuting modes of respondents in Shenzhen.
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The green bar and the percentage number showed the proportion of choices made by the respondents (multiple choices).

In 2016, more than 40% of the trips were made in private cars. With the construction of the railroad in Shenzhen, the proportion of public transport has increased significantly, which is also in line with the development of intelligent urban transport driven by digital technology. The convenience and shorter commute time of green transportation have increased the willingness of private car owners to choose green transportation.

Finding 2: convenience, safety and weather are the main factors respondents consider when choosing mode of transportation

A deep dive into the influencing factors considered by respondents in selecting the transportation means can find that convenience was one of the factors most considered by respondents, accounting for 48.7%, followed by safety, accounting for 34.3%, followed by weather factors (29.6%), comfort (28.7%), low cost (27.6%), low carbon and environmental protection (27.3%), short time (25.9%), and randomness (24.5%), in sequence (see Fig. 3).

Fig. 3: Convenience, safety, and weather were the top three factors considered by respondents when choosing a mode of transportation; other factors included comfort, cost, environmental impact, time, and flexibility.
Fig. 3: Convenience, safety, and weather were the top three factors considered by respondents when choosing a mode of transportation; other factors included comfort, cost, environmental impact, time, and flexibility.
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The green bar and the percentage number showed the proportion of choices made by the respondents (multiple choices).

Finding 3: most respondents are willing to support and engage the national “green transportation” action

In response to the National Green Public Transportation Action and the City’s achievement of its “dual carbon goals,” 67.2% of respondents indicated that they would switch from their original carbon-intensive modes of transportation to a more environmentally friendly, low-carbon mode of transportation. 26% of respondents said they were likely to switch, only 6% said they were unlikely to switch, and only 1.4% said they would not change their mode of transportation. Of the respondents who said it would be impossible to change their mode or that they would not, 58% considered commute time and would not give up that time for green and low-carbon transportation.

About half of the respondents were willing to choose an environmentally friendly mode of transportation recommended by digital maps when the distance to their destination was within an affordable range. The commute time for public transportation was acceptable. These respondents accounted for 51.8%, followed by low carbon and environmental protection at 47.6% and fitness at 35.6%. The remaining factors were low fares and cost efficiency (33.5%), high punctuality, no worries about congestion (33.3%), randomness (32.5%), and high safety (23.3%).

Finding 4: most respondents are willing to adopt green transportation empowered by mobile technology, including the “green transportation” function with the mobile navigation applications

Over 80% of respondents favor digital map navigation applications whose design encourages the use of green transportation features. Providing real-time bus information and transfer information for buses and subways through map navigation software can improve the convenience of public transportation and reduce the time spent on public transit (refer to Fig. 4 for details).

Fig. 4: Over 80% of respondents favored mobile applications that support green transport, such as those providing real-time public transit information, reducing transit time and enhancing convenience.
Fig. 4: Over 80% of respondents favored mobile applications that support green transport, such as those providing real-time public transit information, reducing transit time and enhancing convenience.
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The percentage numbers showed the different degrees of preference (single choice).

Moreover, the functions of retrieving real-time public transit communication information (46.2%), dynamically updating real-time traffic information (45.3%), and recording calories burned while biking and walking (43.5%) made it more attractive for respondents to choose a green mode of transportation.

Finding 5: models such as carbon inclusion and carbon accounts give users a strong sense of gain about green transportation

Personal carbon reductions (or credits) with a specific transaction feature were more appealing to respondents compared to honorary certificates and the ranking list. 67.7% of respondents felt that the newly added personal carbon reduction could be used in digital card navigation applications for trading or exchanging cash, consumer vouchers, and other items, making it more attractive for them to choose green transportation (Fig. 5). Among them, 68% of supporters were 39 years old or younger.

Fig. 5: Personal carbon reductions with transactional features are preferred over honorary certificates and ranking lists.
Fig. 5: Personal carbon reductions with transactional features are preferred over honorary certificates and ranking lists.
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In all, 67.7% of respondents preferred the addition of personal carbon reduction in digital navigation apps for future trading or cash exchanges appealing, thereby encouraging them to choose green transportation. The green bar and the percentage number represented the proportion of features respondents’ preferences (multiple choices).

Respondents also believed that setting up a personal carbon account to show personal carbon reduction (57.0%) and donating their carbon reduction to charitable projects (48.9%) could encourage their willingness to adopt green transportation. Recognition of carbon reduction incentives and green transportation by friends and society could make it easier for users to choose green transportation.

Finding 6: Tencent Maps green transportation portal can effectively enhance users’ willingness to use green transportation

Among the respondents who have used Tencent Maps, 34.5% have noticed and frequently used the green traffic portal, 30.9% have noticed it occasionally, 16.7% have noticed but never used it, and 17.9% have not noticed and used it. This shows that the majority of users have noticed the green traffic portal and used it. The survey of those who have used the green traffic module of Tencent Maps showed that more than 90% of the respondents thought that the module had made the trip more convenient and promoted their awareness of green travels (see Fig. 6 for details).

Fig. 6: Tencent Maps’ green transport portal has enhanced users’ propensity towards eco-friendly travel.
Fig. 6: Tencent Maps’ green transport portal has enhanced users’ propensity towards eco-friendly travel.
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Over 90% respondents agreed that it improved their journeys and heightened their awareness of green travel. The green bar and percentage numbers showed the proportion of respondents’ approval status (single choice).

Additionally, more than 90% of respondents who have used green transportation modules felt that they have contributed to achieving the dual carbon goal, and only 0.5% disagreed with this statement.

Shenzhen has launched an inclusive carbon project earlier than the rest of the country, and the public is more interested in quantifying individual carbon emission reductions. 45% of Shenzhen respondents wanted to know how much carbon reduction they make through the green transportation module, and 40% of Shenzhen users were more interested in the carbon reduction effect.

Finding 7: high satisfaction with the layout and operation of bus and subway facilities in Shenzhen and Beijing

We analyzed the satisfaction level of respondents in Shenzhen and Beijing with their cities’ bus and subway facilities and operations. In total, 89% of respondents in Shenzhen and 87% in Beijing were very satisfied or somewhat satisfied with subway facilities and operations. In total, 85% of respondents in Shenzhen and 83% in Beijing were very satisfied or somewhat satisfied with the facilities and operations of public transit. However, the satisfaction level of the bus was lower than that of the subway, suggesting that people in Shenzhen and Beijing prefer the subway more, which is related to the shorter transportation time of the subway.

Digital maps assist low-carbon public transport: a case study in Shenzhen

This research applied the principle of the voluntary emission reduction methodology with the parameters outlined in the Shenzhen Carbon-Inclusive Methodology for Low-Carbon Public Transportation. The study focuses on calculating the carbon emission reduction facilitated by digital technology in Shenzhen, including:

The emission reduction volume of the subway from January 1, 2019, to December 31, 2021.

Baseline emission:

BE = 25,841,178,916 P km × 0.0812 kgCO2/P km÷1000 = 2,098,304 tCO2e.

Project emission:

PE = 25,841,178,916 P km × 0.0345 kgCO2/P km÷1000 = 891,521 tCO2e.

Emission reduction volume generated by subway transportation:

ER = 2,098,304t − 891,521t = 1,206,783 tCO2e.

The emission reduction volume of the electric bus from January 1, 2021, to May 31, 2022.

Baseline emission:

BE = 1,000,568,937 P km × 0.0812 kgCO2/P km÷1000 = 81,246 tCO2e.

Project emission:

PE = 1,000,568,937 P km × 0.0543 kgCO2/P km÷1000 = 54,330 tCO2e.

Emission reduction volume generated by bus transportation:

ER = 81,246t − 54,331t = 26,915 tCO2e.

The research results show that from 2019 to 2021, Shenzhen citizens reduced CO2 emissions by about 1.2 million tons in 3 years by using the subway through the Tencent Map green transportation platform. Shenzhen citizens had reduced nearly 27,000 tons of CO2 emissions in 17 months since the launch of the digital tool of Tencent Map Bus Code in the city.

Discussion

Practical experiences have shown that the consistent expansion of public transportation systems such as subways, light rail, and rapid bus transit (BRT) is an effective way to save energy and reduce carbon emissions from urban transportation in both developed and developing countries (Chen and Naylor 2011; Li and Luo 2022; Ling et al. 2022). To travel the same distance, the energy consumption of a car is three times higher than that of a bus. Improving non-motorized transportation by building a public transit system will help create an efficient, low-carbon urban transportation system (Energy Research Institute and National Development and Reform Commission 2017; Kepaptsoglou et al. 2020; Kanthavel et al. 2021). In most international metropolitan areas, the share of public transit, including rail and bus, is over 70%, and the percentage of private car travel is relatively low. In New York, for example, the share of private car trips is about 16%, while in Hong Kong, it is only about 11% (Wu and Mao 2019). The share of environmentally friendly transportation in domestic metropolitan areas is increasing, leading to decreased private car travel. However, it reported that the proportion of private car trips in Shenzhen was 41.2% of the total trip rate in 2016, and it was 33.8% of total trips in Beijing were made by private cars in 2017 (Wu and Mao 2019; An and Chen 2021).

Digital technology and digital tools could help popularize green transportation and implement cities’ carbon emission reduction goals.

First, digital technology improves transportation convenience and shortens commute time, which are the key factors that lead users to choose green transportation. Environmentally friendly transportation is increasingly becoming one of the Chinese transportation industry’s key measures to address climate change and for cities to achieve sustainable development. Compared to cities in developed countries, the proportion of private transport in Chinese cities is currently relatively high. The state is also introducing a series of measures to increase the proportion of green urban transport, which will help achieve the city’s “carbon emission reduction goals.” Under the ongoing Clean Urban Transport Action (Ministry of Transportation and National Development and Reform Commission 2020), 109 cities will set their clean transport targets to help reduce carbon emissions in the city. It is necessary to encourage a large number of citizens to use environmentally friendly public transport. By increasing the proportion of environmentally friendly transportation, the potential for reducing carbon emissions is worth the wait.

For most citizens, the convenience of transportation and travel time are important factors. Only by improving the convenience of public transportation and reducing transfer and waiting time can passengers reduce or even abandon private car use and switch to environmentally friendly transportation (Swierstra et al. 2017). Most residents seek houses closer to bus stops or desire housing with high-frequency train service and more activities nearby (Meng et al. 2021). Given the level and trajectory of development of Shenzhen and other metropolitan cities, the share of rail transportation in environmentally friendly transportation is expected to increase. Owing to the uneven distribution of rail transit, the convenience of rail transit is the key factor in ensuring that users are willing to use green transportation.

In the survey, we found that for young users, the inclusive carbon incentives and mental recognition that green transportation brings are the most critical factors that drive them to choose green vehicles. Inclusive carbon is becoming one of the most important measures to create green urban transportation. Shenzhen and other cities led the way in publishing and providing standard support for the methodology for incorporating CO2 emissions into green urban transport.

Second, digital technology has become the primary means to promote green transportation. Previous researches indicated that autonomous vehicles, in the form of autonomous shuttle buses, could increase public transport coverage and patronage, and hence decrease the carbon emissions associated with transport (Faisal et al. 2019; Yigitcanlar et al. 2019). In contrast, autonomous vehicles—in the form of private autonomous cars—could increase mobility and urban sprawl, and thus increase transport carbon emissions (Butler et al. 2021). Issues similar to these bring up the need for technological innovation in the context of cities, or in other words urban innovation, to become responsible for maximizing the desired outcomes and positive impacts for all and minimizing the unwanted ones (Yigitcanlar et al. 2021). The application of digital technology can improve the convenience of public transit and shorten the waiting time of users in public transit through real-time bus and subway information. In particular, the emergence of a one-stop full-scenario platform for “green transportation” allows users to plan bus routes easily, shorten bus and subway station waiting times, make payments, and improve the efficiency of green transportation. In the case of Shenzhen, the share of private car traffic was nearly 40% in 2016. At present, the proportion of public transport has increased significantly. In 2025, the proportion of environmentally friendly transportation in Shenzhen will reach 81% (Shenzhen Government 2022). In our survey, the proportion of respondents who use public transportation in Shenzhen was nearly 93%. Digital technology and digital tools have significantly contributed to promoting the green transportation rate in Shenzhen in recent years.

The survey was conducted during the COVID-19, in which period that the proportion of Chinese adult residents who choose to travel by foot and car (taxi and private car) is much higher than that during the non-epidemic period, while the proportion of people who choose public transportation, bicycle or electric vehicle and other transportation modes is lower than that during the non-epidemic period (Jiang et al. 2020). Covid-19 was possible to reduced the positive impacts of using digital tools, presented in the result section when all economic activities were closed in China. But efforts to reduce consumer-end carbon emissions were not stagnated.

On September 8, 2020, the Beijing Municipal Transport Commission and the Beijing Municipal Bureau of Ecology and Environment, together with AutoNavi Maps and Baidu Maps, launched the “MaaS Transportation-Greening the City” campaign and, for the first time, provided incentives for green transportation that include carbon consumption. When citizens travel by bus, subway, bicycle, foot, or other green transportation, they can use digital tools, such as AutoNavi Maps and Baidu Maps apps, for route planning and navigation and receive the corresponding credits for reducing carbon emissions after the trip. As of March 23, 2022, the number of officially registered users of the “MaaS Mobility-Greening the City” activity was over one million, with 420,000 monthly active users. The cumulative carbon emission reduction was nearly 100,000 tons, of which 24,500 tons of carbon emissions had completed emissions reduction trading (Beijing Municipal People’s Government 2022).

On April 29, 2022, the group standard “Guidelines for Quantifying the Reduction of Greenhouse Gas Emissions by Green and Low-Carbon Behavior of Citizens” developed by the All-China Environmental Federation (ACEF) (2022) was published to quantify and evaluate the reduction of carbon emissions by green behavior of citizens, encourage the public to green behavior, promote the widespread formation of green lifestyles and contribute to the “dual carbon goals.” The Center for Environmental Education and Communication of the Ministry of Ecology and Environment (CEEC), China Internet Development Foundation, Chinese Academy of Environmental Planning of MEE and Special Committee on Green Cycle of ACEF, together with Peking College, Tsinghua College, Renmin College and Green Inclusive, Meituan, Alibaba, Tencent, JD.com, National Energy Group, China Environmental United Certification Center (CEC), Beijing Green Exchange and other survey agencies (including more than 20 industry experts) officially released the report, providing a “ruler” for measuring carbon emission reduction in the consumer sector. It is another attempt by the government, social organizations, enterprises, and other forces to build consensus, collaborate and support the implementation of the carbon emissions inclusion mechanism. The participation of many social groups and enterprises has laid an excellent practical foundation for the successful publication of the guidelines and smooth implementation in the future.

Conclusion

Digital tools such as Tencent’s Low-Carbon Planets have become popular among young people in Shenzhen. Within 6 months after launch, nearly one million Shenzhen citizens participated in carbon reduction through the “Low-Carbon Planet” initiative, taking a cumulative 1.4 billion steps and taking public transportation or subway through Tencent Maps. To attract the younger generation to actively embrace green travel in the future, fun digital emission reduction and recording tools are essential. The “low-carbon planet” approach has achieved good results in Shenzhen, and in the future, it can promote the integration of such products with local green travel creation plans, giving the younger generation more motivation for green travel. Government, social organizations, enterprises, and other stakeholders need to cooperate with digital technology enterprises, formulate low-carbon living behavior emission reduction standards represented by green transportation, and develop low-carbon behavior emission reduction certification methodologies in carbon inclusion pilot cities to enable the public to feel a sense of gain from green transportation with the assistance of digital tools.

Future studies and Implications

This study aims to understand the public’s willingness to use green transportation and the role of digital tools in green travel, and thus understand the current status and opportunities of green travel for the public. It is also using Shenzhen as a pilot to understand the role and opportunities of digital map tools in the creation of green transportation sector in the big cities of China. In the next step, it will be important to work with digital technology companies to formulate detailed rules for inclusive carbon groups in green living, gradually build a national system for inclusive carbon standards and trading market, and develop relevant methods for validating activities and verifying emission reductions for green transportation in more pilot cities, so that inclusive carbon reduction policy can be replicated in more cities across the country and the public can get a sense of benefit from green transportation.