BIM and GIS Applications in Bridge Projects: A Critical Review

: In recent years, interest in BIM and GIS applications in civil engineering has been growing. For bridge engineering, BIM/GIS applications such as simulation, visualization, and secondary development have been used to assist practitioners in managing bridge construction and decision-making, including selection of bridge location maintenance decisions. In situ 3D modelling of existing bridges with detailed images from UAV camera has allowed engineers to conduct remote condition assessments of bridges and decide on required maintenance actions. Several studies have investigated the applications of BIM/GIS technology on bridge projects. However, there has been limited focus on reviewing the outcomes of these studies to identify the limitations of BIM and GIS applications on bridge projects. Therefore, the aim of this study was to review the research on BIM/GIS technology applications in bridge projects over the last decade. Using a systematic review process, a total of 90 publications that met the inclusion criteria were reviewed in this study. The review identiﬁed the state-of-the-art methods of BIM and GIS applications, respectively, at the planning and design, construction, and operation and maintenance phases of bridge projects. However, the ﬁndings point to segregated application of BIM and GIS at all phases of bridge projects. The ﬁndings of this study will contribute to guiding practitioners in selecting appropriate BIM and GIS technologies for different aspects of bridge projects.


Introduction
Building Information Modelling (BIM) and Geographical Information System (GIS) are two interdisciplinary scientific fields that involve the application of computers to integrate and visualize diverse project data and provide an objective source of project information to assist managers in making project decisions. At present, BIM/GIS technology is used in several fields, including architecture, civil engineering and facilities management. This paper mainly discusses the research and application of BIM/GIS technology for bridge projects.
BIM has the potential to improve the efficiency and effectiveness of the design of mega-complex bridge projects [1]. A design guideline of 3D information models was suggested [2]. Three-dimensional bridge models enable digital mock-ups and design enhancements [3]. A modern, technologically-advanced design may be compatible with feasible solutions [4] to help governments, urban planners and other stakeholders in making bridge project-related decisions [5,6]. The use of BIM may facilitate otherwise complex projects [7] to shorten the construction time and reduce cost by minimizing trial and error [8]. The application of 4D Bridge Information Modelling (BrIM) in the construction phase benefits the project team in material delivery planning, project monitoring and control, construction schedule improvement, documentation and coordination [9]. BIM implementation may lead to 5-9% cost savings during construction through reduced change orders and rework [7] that would enhance cost-effectiveness and sustainability outcomes [10,11]. Additionally, significant benefits such as enhanced structural health monitoring may be realized through a future BIM-enabled operation and maintenance of such an infrastructure [7,12]. GIS implementation contributed to reducing the cost and increasing the accuracy and timeliness of the project and program development of major transportation infrastructure programs [13,14]. Integrating BIM and GIS may improve the efficiency of infrastructure operation management by providing a useful platform [15] that furnishes engineers and other decision-makers with detailed information about specific issues [16]. System information requirements would need to be defined by stakeholders and a unified format adopted to facilitate data exchange [17]. Semantic integration of cross-domain data is trusted to be highly automated [18] and the generated BrIM based on industry foundation classes (IFC) can be queried semantically [19]. IFC are used to exchange information; the implementation of asset management properties can facilitate a transition from document-based software to a combination of visual representation alongside the information that accompany every asset to form a basis for integration with GIS standards such as CityGML, and investigated to determine the level of information transferred between the BIM and GIS standards [20]. Managers explore more features of a bridge information model [21] at the asset management phase to aid efficient and informed decision making [22]. Information modeling is more than just a new technology-it is a new way of working [23] which has the power to totally transform the bridge industry.
Over the last decade, the application of BIM/GIS technology in the planning and design, construction, operation and maintenance as well as information exchange on bridge projects has increased significantly. The potential benefits of applying either BIM, GIS or both technologies on bridge projects cannot be overemphasized. However, the literature is limited regarding studies that have focused on reviewing outcomes of BIM and GIS applications on bridge projects. A review of these studies would lead to identifying BIM and GIS applications that are most suitable for selection of bridge location, budget allocation, and formulation of maintenance decision schemes. Additionally, a review of these studies would lead to identifying weaknesses of current methods of BIM and GIS applications on bridge projects. This information will be relevant to practitioners who are looking to apply BIM and GIS technologies to their bridge projects. Additionally, developers of BIM and GIS technologies can use this information to develop the next generation of BIM and GIS technologies to overcome the limitations of the current methods. Therefore, the purpose of this study was to review the application and potential capabilities of BIM/GIS technology in different aspects of bridge projects, and to determine the value and implications of these technologies for decision making and management of bridge projects. The vision of BIM/GIS applications for bridge projects would be to aid the development and optimization of new construction processes to reduce project duration, construction cost, site safety and environmental impact of the bridge construction. Additionally, BIM/GIS would seek to optimize operation and maintenance processes using emerging methods such as omnidirectional data acquisition to aid real-time remote condition inspection and data collection. To achieve these visions, there will be a need to develop BIM and GIS standards and formulate standardized bridge design modeling protocols and terms. Section 2 below describes the research methods used in this review while Section 3 presents the analysis in four aspects as follows: (1) planning and design stages, (2) the construction stage, (3) operation and maintenance stage, and (4) information exchange. Section 4 discusses the challenges associated with these four aspects and suggests possible directions for future research.
This study analyzed and consolidated the current state-of-the-art on the application of BIM and GIS technologies on bridge projects. This review contributes to the literature by highlighting the limitations of the current BIM and GIS applications on bridge projects. The limitations identified in this review highlight the current research gaps and will contribute to shaping the direction of future research on BIM and GIS applications on bridge projects. Additionally, this review will guide bridge engineering industry practitioners in choosing appropriate BIM/GIS tools for relevant applications on bridge projects.

Research Methods
This research conducted a systematic review following the PRISMA framework to obtain a comprehensive understanding of how BIM/GIS technology is utilized on bridges. Data for this systematic review were sourced mainly from Scopus because of its broad coverage of interdisciplinary research. Google Scholar, a powerful web search engine, functioned as a supplementary tool to eliminate searching biases. "Building Information Modelling" (BIM) or "Bridge Information Modelling" (BrIM); "Civil Information Modelling" (CIM), or "City Information Modelling" (CIM); "Geographical Information System" (GIS), and bridge constituted the primary keywords. The "AND" Boolean logic was used to search for combinations of the primary keywords in either the title, abstract or keyword fields of journal articles to capture a wide range of sources relevant to the applications of BIM and GIS technologies in bridge construction and management. The time frame for the review was set to the past ten years (2011-2020) since BIM/GIS technology is a relatively new area that is largely facilitated by the development of computer science. The publication type was limited to peer reviewed journal articles to ensure that high-quality state-of-the-art research was reviewed. Figure 1 presents details of the PRISMA framework implementation in this research. A total of 135 records were retrieved from Scopus and 96 from Google Scholar. The records retained for screening after removing duplicates was 124 journal articles. After screening titles and abstracts, 113 records were retained for full-text review as shown in Figure 1. Records were retained for detailed qualitative synthesis if they collected and analyzed BIM/GIS technology implementation data on bridges. A total of 90 publications were retained for detailed review following a full-text eligibility review.
by highlighting the limitations of the current BIM and GIS applications on bridge projects. The limitations identified in this review highlight the current research gaps and will contribute to shaping the direction of future research on BIM and GIS applications on bridge projects. Additionally, this review will guide bridge engineering industry practitioners in choosing appropriate BIM/GIS tools for relevant applications on bridge projects.

Research Methods
This research conducted a systematic review following the PRISMA framework to obtain a comprehensive understanding of how BIM/GIS technology is utilized on bridges. Data for this systematic review were sourced mainly from Scopus because of its broad coverage of interdisciplinary research. Google Scholar, a powerful web search engine, functioned as a supplementary tool to eliminate searching biases. "Building Information Modelling" (BIM) or "Bridge Information Modelling" (BrIM); "Civil Information Modelling" (CIM), or "City Information Modelling" (CIM); "Geographical Information System" (GIS), and bridge constituted the primary keywords. The "AND" Boolean logic was used to search for combinations of the primary keywords in either the title, abstract or keyword fields of journal articles to capture a wide range of sources relevant to the applications of BIM and GIS technologies in bridge construction and management. The time frame for the review was set to the past ten years (2011-2020) since BIM/GIS technology is a relatively new area that is largely facilitated by the development of computer science. The publication type was limited to peer reviewed journal articles to ensure that high-quality state-of-the-art research was reviewed. Figure 1 presents details of the PRISMA framework implementation in this research. A total of 135 records were retrieved from Scopus and 96 from Google Scholar. The records retained for screening after removing duplicates was 124 journal articles. After screening titles and abstracts, 113 records were retained for full-text review as shown in Figure 1. Records were retained for detailed qualitative synthesis if they collected and analyzed BIM/GIS technology implementation data on bridges. A total of 90 publications were retained for detailed review following a full-text eligibility review.  To analyze these publications quantitatively, Table 1 lists journals where the reviewed papers were published, including top ranking journals such as Automation in Construction (AIC), Journal of Computing in Civil Engineering (JCCE), and Structure and Infrastructure Engineering (SIE). The paper distribution in terms of year and journal is illustrated in

Analysis
Bridge engineering involves many stages throughout its life cycle; each stage comprises multiple complex processes with large project teams and relies on the efficient exchange of information [24][25][26]. Table 2 shows the distribution of the reviewed studies with respect to planning and design, construction, operation and maintenance, and information exchange for the last decade.

Planning and Design
Because GIS technology has the function of a macro layout, it is often used in the regional level and above scenes, as Table 3 shows that the application of GIS technology in bridge engineering at the planning stage mainly involved making need-based decisions for planning new bridges [6,66,67] to improve transportation infrastructure [6,66], traffic jam and pedestrian travel time [67]. Additionally, GIS technology combined with different multi-criteria decision-making methods were used in selecting the best geographic locations for new bridges [5] to minimize cost and also add value to the city image [4] and other benefits (e.g., tourism). • Parametric modeling is mainly used in regular components, but it lacks the application in special-shaped components. • The effective application of three-dimensional information modeling and DMU technology in segment manufacturing and bridge transmission is still limited by many factors, such as unskilled operators.
[4] Aesthetic • Showed that a modern, technologically advanced design may be compatible with a solution whose elegance meets the most exacting aesthetic standards.
• Holistic consideration of the natural, human and built context of civil works generally neglected in structural engineering.
[11] Design model integration • Lack of the effect of incorporating complex quality functions on prioritizing MR and R decisions for bridge components.
[28] Conceptually plan • By integrating 4D BrIM, assisted stakeholders' conceptual plan with cost data resources, besides user-defined input, is presented.
• Lack of invasive research on integration of bridge information modeling, fuzzy logic decision support and cost estimation system.

Technology: GIS
Bridge location • GIS technology combined with five different multi-criteria decision-making methods could facilitate effective selection of pedestrian bridge location.
• Lack of dynamic analysis of the impact of bridge site selection on planning. [6,66] Road transport information management system • GIS for data collection, entry, management and analysis will facilitate planning and development of road transport infrastructure and ease management and control of its facilities.
• Would need industry-wide adoption of GIS. [67] Transportation network • GIS model projected 50% reduction in pedestrian travel time (i.e., minimize pollution and fuel consumption).

•
Reduced congestion in current bridge approaches.
• Calculation time of model is long. • Based on the strong space data management and information process of GIS, the GIS of HEBC was constructed, and its evaluation was effectively realized.
• Input and output mode of GIS data have not been fully automated. Table 3 also shows that use of BIM technology at the design stage of bridge engineering has focused mainly on developing and using 3D bridge models to inform design decisions. The authors of Refs. [11,23] used a 3D information model to analyze the assembling process of a bridge and suggested modifications. The authors of Refs. [1][2][3]8] conducted the parametric modeling of a bridge and suggested a design guideline for 3D information modelling to reduce collision and other modeling problems to enhance the accuracy of 3D model design. Three-dimensional information modeling can also be used to design aesthetically pleasing bridges [4]. The authors of Ref. [27] proposed that an integrated information management system at the conceptual design stage should become the new approach to informing downstream design (and construction) processes of bridge projects. Based on the powerful spatial data management and information processing ability of GIS, Ref. [68] constructed the evaluation model of highway engineering bearing capacity (HEBC) based on GIS, and effectively realized the evaluation of highway engineering bearing capacity. Table 4 shows applications of BIM/GIS technology at the bridge construction stage from 18 studies. Among them, only one study [69] investigated the application of GIS technology combined with fuzzy logic in the selection of better bridge construction location in the construction process. At the construction stage, Table 4 shows that research on the application of BIM/GIS technology has focused mainly on construction cost [3,7,10,29,30], scheduling [1,3,7,9,10] and visualizing the construction process on site [1,2,8,9,[31][32][33][34][35] and is not surprising, given that these are among the key issues that project managers will generally prioritize at the constructions stage of all projects, including bridges. However, the table also shows the use of BIM/GIS technology for other complex tasks at the construction stage, including coordination [9,11], optimizing constructability [21,69], and tracking GHG emissions [69].  • Understanding of 3D model technology and assurance of positive effects of its application were insufficient.

•
Use of BIM may facilitate scheduling of complex projects and saved approximately 5-9% cost by contributing to reduced change orders and rework.
• About 70% of the cost of 3D modeling may be associated with the first implementation; this front-end loading of 3D modeling cost may limit its adoption.
[8] Risk factor • The risk visualization system not only quantifies risk factors reasonably but also visualizes existing mathematical modes of expression.
• Category of risk factors is not applicable to a wide range of bridge engineering.
[9] Construction sequence, schedule • Lack of quantitative evaluation of 4D BrIM application benefits.
[10] Rework • Six-dimensional BIM can save time by transforming 2D information to 3D information. • Collaborated within 6D BIM environment can reduce the rework amount and lead to enhancing sustainability and cost-effectiveness of outcomes.
• Lack of compatibility with complex bridge modeling would result in some unnecessary rework. [21] Crane location • Choosing the best crane position using a 3D model can be enhanced by importing the crane model and simulating the erection process.
• Hybrid model needs more projects to verify its applicability.
[29] Budget, schedule • Current open BIM standards (e.g., IFC) do not define schemas for risk management. Project participants used BIM technology to calculate the required earth filling [53,54], timely visualize of risk factors [8], select the best crane position through the visualization [21], minimize rework [7,10], track project schedule [1,3,7,9,10], and to finally reduce construction cost [3,7,10,29,30]. BIM can also generate as-built CAD drawings from as-built BIM models [2] and export them. Table 5 shows the operation and maintenance applications of BIM/GIS technology in bridge projects from 41 studies. Among them, only one study [15] focused on the bridge management system (BMS) and investigated the application of BIM and GIS technologies to realize several maintenance functions, including information management, bridge detection, condition evaluation, repair and reinforcement, multi-scale visualization, and collaborative management. At present, GIS technology is mainly used for tracking bridge traffic networks [13,[70][71][72][73][74][75][76]. This traffic network can be leveraged by disaster response systems to determine the location of the affected bridge [14,77,78] and coordinate the timely arrival of first responders, such as firefighters [70], to minimize disaster-related losses [13,74]. Table 5. BIM/GIS uses in operation and maintenance.

Examples Application Type Key Outcome Limitations
Technology: BIM [12] Operation and maintenance cost

•
Accurately predicted the operation and maintenance cost of target projects.

•
Through the actual data, the effect of operation and maintenance management was verified and operation and maintenance cost was reduced.
• Actual project defects not considered.
[16] Automatic rule checking • Bridge maintenance regulations were translated into a machine-readable language to realize automated rule checking and eliminate unnecessary subjective errors.
• Realizing automation in all maintenance phases could be challenging.

•
Converting information from Revit models into ontologies without data loss may be less likely.  [17,36] Operation and maintenance cost

•
A bridge data management system could significantly help engineers to save time and money on inspection and repairs.
• The process method is theoretical without practical proof of concept. [34,37,38] 3D in situ modelling • UAV was used to acquire images from all possible points of view, overcoming limited inspection accessibility and occlusions, which provides the completeness and accuracy needed for both detailed 3D in situ modelling and structural condition assessment.
• Mature shrubs will cover the structure and hinder the acquisition and imaging.

•
Bottom of decks on cloudy days will be difficult to capture. [39,40] Bridge evaluation • BIEM (bridge information modeling for inspection and evaluation method) provides a way to collect, store, and use location based damage information from a bridge inspection by using BIM software to analyze and present that information to help make decisions by enabling the user to evaluate damages on the basis of location and providing maintenance recommendations.
• There is no automatic algorithm to extract and manage data for BIM storage or to solve the analysis structure evaluation process. [41,42] Maintenance scheduling • Maintenance engineers were able to perform their daily tasks in nearly 50% less time and with 20-40% higher accuracy.
• Lack of 4D technology based on the impact of maintenance data to communication between maintenance engineers.
[43] Bridge evaluation • Random spatiotemporal conflict detection method can effectively calculate the random conflict probability due to the change of reconstruction task duration, and can assist decision makers to investigate different demolition start dates.
• Lack of different resource quantity constraints.
[44] Bridge inspection • A chain of algorithms based on a computer vision was embedded into an AR device that aims to enhance the precision and performance of inspection tasks. After, the technical damage report is fed-back to the management system and is available for assessment and discussion.
• The reliability of this inspection system will depend on the capability of the AR device and the strength of the network connection.
[45] Bridge evaluation • Proposed idea (unique integration of structural health monitoring and resulting dynamic information) would enable systematic visualization of condition assessment data that are collected on a continuous basis.
• Needs to be updated with the changing environment. [46] React to unexpected situation • Federated model using DTM/RTM provides an information-rich resource for maintenance purposes. • Accumulated damage and repair history was retained; this significantly supports the project team to react timely against unexpected situation, as well as creating a premise to orient a long-term strategy for bridge maintenance.

•
Maintenance performance was significantly improved due to the federated models.
• Accuracy of mechanical twin model is not enough. • Need the actual data to verify the reliability of the model and conclusion.

•
Deflection measurement error between imaging instrument and special bridge deflection measurement instrument was only 3.0% to 6.9%.

•
Balanced decision making proposed for bridge maintenance management strategy based on several constraints, including cost optimization and decision support from professionals. • Influence of uncertain storm factors is not considered.
[73] Bridge evaluation • System developed for prior identification of vulnerable components whose failure due to a major earthquake event may have disproportional socio-economic impact.
• The threshold value (capacity) of each component needs to be modified with more cases.
[75] Bridge evaluation • Assessed regional network resilience by leveraging scenario-based traffic modeling and GIS techniques.
• There are limited records of bridge closure times, especially after dangerous events.
[76] BMD • Determined optimal intervention programs for large infrastructure networks using a linear optimization model.

•
Application of mixed integer nonlinear model is not considered. [77] Disaster response system • Mobile disaster response system not only reports sudden disaster information, but also offers precise disaster locations.

•
The speed of information feedback still needs to be strengthened. • Developed a GIS-based multi-criteria decision-making system without extra data collection effort while yielding high confidence in obtaining optimal prioritization solutions for bridge maintenance and repairs. • GIS interface can easily visualize bridge information and facilitate the decision-making process.
• Lack of dynamic analysis of the impact of bridge site selection on operation and maintenance.
[52] BMS • Database management system that can house basic information about a bridge, the inspection record, maintenance and reinforcement history, and images; system provides a variety of information queries and automatically generates documentation needed for a comprehensive bridge evaluation.
• More projects are needed for application. [84] Bridge evaluation • Network map reconstructed using GIS data; when the intensity of ground motion is determined at the locations of a bridge, the probability of damage can be calculated from seismic fragility curves.
• GIS and ANN technologies need to be applied to more projects to verify their adaptability.
[85] BMS • Makes BMMS more interpretable through dynamic color coding and more sophisticated visualization techniques than the conventional tabular data format.

•
Geostatistical analysis was carried out in which the settlement of study areas were defined by producing color images.
• There are still some inaccuracies in local color coding.
[86] BMD • Decision making tool for the renovation of obsolete bridges and tunnels.

Information Exchange
• Digital models need to be updated by adding more information on their performance.
[19] IFC standard • Developed rules of unique identifier and information reassignment, and applied a semi-automated naming algorithm.

•
It was observed that information retrieval and extraction for components was possible through a semantic-based query to the generated IFC-based bridge information model.

•
It is still insufficient for implementing true BIM models owing to the absence of support of IFC for bridge structures. • BrIM considers only a few standards and applications. • Requires creating data retrieval scripts.
[41] Data integration • Four-dimensional modeling has the potential to provide an effective means of sustainable integration of various data categories with 3D models of an infrastructure over its lifetime.
• Needs more focus on the use of interoperable and open data exchange formats.
[46] Interoperability • Mechanical model derived directly from the initial model through the interoperability of BIM solution which created the DTM; this can maintain the integrity of the 3D physical models.
• Data management system of network layer lacks automatic and timely update of information.
[55] Expand standard • Developed a process that results in a rule set to identify all possible object types in a domain.

•
Object can be completely and correctly classified only when the models have sufficiently small errors in the locations and geometry of the bridge components to allow the geometry and topological relationship operators to perform correctly with suitable tolerances.
• Success of the object classification process remains dependent on the quality of the geometric model. [56] Expand standard • Presented taxonomy of geometrical models and notation of distinguished classes of geometry representations to enable consistent and uniform classification of all models used.

•
Classification system can be used for homogeneous and non-homogeneous models.
• Bridge structure representation may not meet the increasing accuracy and complexity. [57,58] Data integration • Damaged data structure and semantics definitions proposed. • It is possible to either apply the proposed approach to an external IFC file and simply link it with BMS or insert an IFC representation of every specific bridge into the BMS.
• Lack of digital drawings or even the paper ones makes this task rather difficult although the registration precision is achieved.
[63] Interoperability • Engaged bridge industry stakeholders in vetting data exchange requirements and aided eventual compliance certification processes.
• Incomplete data exchange between two or more stakeholders. • There are still some problems in the construction of common vocabulary, such as low efficiency and automation. [87,88] Data integration • Multiple technologies integrated to enhance the accuracy and reliability of the collected data.
• There is a phenomenon of manual processing in data integration.
[89] Interoperability • Reconfigured the way that people interacted with spatial data that included multi-sensory engagement, multi-dimensional representation and thinking through play. • Tactile and kinetic engagement were able to interact with landscape information in a shared space.
• Needs to be applied and improved in many aspects.
Technology: BIM and GIS [15] IFC expansion • Necessary IFC and IFD standards were proposed as supplements according to the actual maintenance needs of bridges; thus, filling the gap in BIM standards of the bridge industry in China.
• IFC has not fully expressed its bridge attribute in China. [90] Interoperability, data integration • Transformation of IFC to shapefile achieved with opensource technology and is more stable and efficient than that of the DIA. • Shapefile supports 3D geometry and can be exchanged easily with other non-GIS 3D software packages.

•
As an open-source solution for transforming IFC to shapefile, the proposed method can contribute to the community and advance BIM/GIS integration.
• Transformation is currently unidirectional from IFC to shapefile in terms of geometry. • Efficiency of BIM/GIS integration should be further improved.

Discussion and Future Work
BIM and GIS modelling are new techniques that require further investigation to discover their potential benefits for all stakeholders [91,92]. The integration of both technologies is expected to revolutionize digital design in the Architecture Engineering Construction (AEC) industry [10,93]. Table 7 shows the challenges and potential solutions for the effective application of BIM/GIS technology in the bridge sub-industry of AEC based on synthesis of the limitations of the application of BIM/GIS technology from the current body of knowledge. The following four subsections expand these challenges and suggest potential solutions.

Planning and Design
It was found that most practitioners only considered BIM as a display tool and some of them had no idea about BIM [1]. With the increase in population and the evolving complexity of structural design [4], there is the need to improve practitioners' knowledge and application of BIM/GIS technology [1] to enhance the application of BIM/GIS technology at the design stage of bridge projects [4,6,11,66].
The design institutions need to regularly train and assess practitioners in the application of BIM/GIS technology [1]. At present, efforts are being made to expand the probabilistic and numerical model database of bridges, which is an important step towards formulating reasonable design rules for bridge components [27]. This can be achieved through close cooperation between key stakeholders, including architects [4], landscape designers and urban planners.

Construction
The application of BIM/GIS technology in the bridge construction process in various countries is increasing. This can promote effective and efficient management of the construction processes and contribute to further development of BIM/GIS technology for the AEC industry and particularly, the bridge sub-industry. However, there are several technical and practical problems that need to be resolved to enhance the application process of these technologies.
About 70% of the negative cost impact of some bridge construction projects may be related to the first implementation of BIM/GIS technology during construction [7]. Some bridge construction projects use BIM technology to evaluate cost inaccuracies [28][29][30], such as estimates limited to direct costs only [29]. Moreover, due to the lack of BIM/GIS knowledge of bridge project participants [1], the efficiency and effectiveness of BIM/GIS technology implementation may be negatively affected [3,7]. It is gratifying that the visualization of BIM/GIS technology can enhance project cognition and communication among participants in the process of bridge construction [9]; however, only a limited number of bridge projects have implemented BIM/GIS technology [9,21,28,30,69].
It is difficult to completely isolate the impact of BIM/GIS implementation, because no two construction projects are identical [7]. However, in the future, when BIM/GIS technology is used at the construction stage of bridge projects, appropriate BIM/GIS training could be conducted for participants to enhance implementation [1]. Methods of cost estimation can be continuously explored to enhance cost efficiency [28][29][30] by covering most indirect costs [29] so as to reduce the negative cost impact of BIM/GIS technology implementation. BIM/GIS technology implemented on existing bridges for functions such as maintenance management to aid further adaptation of these technologies for bridges and continuous improvement of the application process.

Operation and Maintenance
At present, the existing bridge transportation network models based on GIS usually adopt deterministic [71,72] or static traffic flow patterns [76], without considering the influence of other factors, such as wind intensity [70]. The benefits of GIS technology in the management of major transportation facilities have not been verified [13,74]. BIM/GIS models for bridge management have poor compatibility with other models or modules such as the finite element model [15,39,40], damage model [16], and disaster model [14,77,78] and, therefore, influences data mining. There is a growing trend using UAV and other detection technologies for bridge detection based on BIM/GIS [94]. Although these technologies have many benefits, there are some shortcomings, including the lack of overall perspective [41,42] and the impact of weather changes on data quality [14,34,37,38,77,78]; these can affect bridge evaluation outcomes [73]. Therefore, the existing evaluation models may not be directly applicable to other projects [48,49,52,81], given that they may negatively affect maintenance decisions of other bridges.
In the future, researchers could consider introducing uncertainty [71,72] or a dynamic traffic flow [76] and other factors to improve bridge transportation network models based on GIS to enhance model utility and expand the scope of application. BIM/GIS software, including API, should be further developed to improve their compatibility with other models or modules and enhance data mining for bridge management systems [15,39,40,95]. It is suggested to improve the quality of bridge detection by adding acquisition methods such as omnidirectional acquisition [41,42] and improving data processing methods. In terms of bridge maintenance decision making, more researchers and decision makers need to study and verify different bridge maintenance decision-making objectives and constraints [51], and combine with BIM/GIS technology to improve decision making.

Information Exchange
As a research prototype, bridge information models, in their current state, consider only a few standards and applications. Many data entities, which are necessary to fully support other bridge monitoring and management applications, are lacking [36]. Although BIM based on the IFC data model is the core of information interoperability, due to the lack of IFC support for bridge structure [19,36,44,59] and the target classification depending on the quality of the geometric model [55], it is still not enough to realize a real BIM model [19]. Some existing bridges lack digital drawings and even paper drawings [57,58]; hence, most of the data transmission needs to be manual [18,[33][34][35] which would affect the efficiency of BIM/GIS integration [20,90]. BIM/GIS models have inconsistent data exchange format [41,63] and a slow information feedback speed [77], which affect interoperability between models. The poor interoperability of BIM/GIS software may hinder effective development of related software [22,41,[60][61][62][63][64][65].
Regarding future work, it is important to clarify and pinpoint the requirements that each domain sets, especially if BIM-GIS integration (e.g., geometry conversion [20] and semantic mapping [20,55]) are to be addressed [20]. It is suggested that researchers could develop a more accurate bridge information model with detailed parameter information and determine the model development specifications of existing bridges to meet the needs of stakeholders [34]. It is very important to compare BIM standards (such as IFC) with the infrastructure module of GIS standards (such as CityGML) to determine the most favorable integration degree of these two fields in the field of asset management [15,20,90]. When using BIM/GIS technology, managers need to pay more attention to the use of interoperable and open data exchange formats [41] to enhance the operational efficiency of the platform.

Conclusions
There has been increasing interest in the bridge engineering community to use BIM and GIS for the efficient, automated and intelligent handling of different aspects of bridge projects. This research reviewed a total of 90 journal papers over the past decade and summarized the state-of-the-art applications of BIM and GIS technologies in different aspects of bridge projects (i.e., planning and design, construction, operation and maintenance as well as information exchange). Accordingly, the main challenges were identified and future work is recommended based on the following key aspects: (1) Develop BIM and GIS standards to solve the problems of bridge BIM-GIS data integration and interaction method.
(2) During the planning and design stage, it is necessary to formulate standardized bridge design modeling protocols and terms to solve the problems of bridge modeling design.
(3) During the construction stage, try to use BIM technology to optimize new construction processes and improve the construction schedule, as well as reasonable methods for cost estimation could be continuously explored. (4) During the operations and maintenance phase, the requirements of each management department should be clarified and identified, as well as omnidirectional data acquisition methods should be explored further to enhance the efficiency of managers in decision making. Findings of this research would serve as a guide for bridge engineering practitioners in selecting appropriate BIM/GIS technology for different phases of bridge projects. Additionally, findings of this review would contribute to further research and development to improve the application of BIM/GIS technology on bridge projects.

Conflicts of Interest:
On behalf of all authors, the corresponding author states that there is no conflict of interest.