A History of the American Statistical Association’s Transportation Statistics Interest Group
Building Bridges: Institutional Relationships that Shaped Transportation Statistics Interest Group (TSIG)
From its inception TSIG was defined by its ability to connect communities that had previously operated in parallel. Rather than emerging in isolation, TSIG grew out of sustained engagement with four institutional pillars—each of which provided a different kind of foundation for the group’s development.
- The Transportation Research Board (TRB): A division of the National Academies of Sciences, Engineering, and Medicine—part of the National Academies, a private nonprofit institution—TRB provided TSIG with its first bridge to the applied transportation research community. Through early collaboration with the Statistical Methodology and Statistical Computer Software Committee, TSIG established a visible presence. By attending the January 2001 TRB meeting and all subsequent TRB and Joint Statistical Meetings, Promod Chandhok, PhD, founding Chair of TSIG, ensured that the group was firmly embedded in both professional cultures.
- The BTS Research Grants Program: As a principal statistical agency within the U.S. Department of Transportation, the Bureau of Transportation Statistics (BTS) had already established its Research Grants Program to advance methodological innovation in transportation. Beginning in 2001, under the leadership of Promod Chandhok, PhD, the program broadened its scope, bringing new statistical tools into practice and strengthening ties to the academic community. Its network of grantees flowed naturally into TSIG, supplying both intellectual content and a community of contributors.
- The Academic Community: Anchored at George Washington University, where transportation examples were integrated into graduate level coursework, TSIG drew early strength from teaching and mentorship. This academic base ensured a pipeline of statisticians and provided continuity between research and practice, with faculty and members such as Linda Boyle, PhD; Feng Guo, PhD; Cliff Spiegelman, PhD; Roya Amjadi; and Mike Cohen, PhD illustrating the breadth of academic and professional engagement that sustained TSIG’s growth.
- The Strategic Highway Research Program II (SHRP II): Administered by the TRB under congressional authorization, SHRP II represented one of the most ambitious safety initiatives in U.S. history. Serving on the Safety Expert Task Group for Project S08, Promod Chandhok, PhD, reinforced TSIG’s role in shaping national research priorities. His statistical guidance embedded rigor into the Naturalistic Driving Study and demonstrated how TSIG’s expertise could influence large scale, high impact federal research.
Together, these four bridges—TRB, BTS, SHRP II, and the academic community—ensured that TSIG was more than an ASA interest group. They positioned it as a hub where federal agencies, research programs, universities, and professional societies converged. This networked foundation provided TSIG with both legitimacy and continuity, establishing transportation statistics as a recognized subfield within the broader discipline of statistics and within the organizational framework of the ASA.
TSIG and the TRB: Statistical Methodology and Statistical Computer Software Committee
TSIG traces part of its origin to the TRB’s Statistical Methodology and Statistical Computer Software Committee. At the January 2001 TRB meeting, the session was chaired by Mike Griffith of the Federal Highway Administration, who at that time led the committee. Later that year, at the 2001 Joint Statistical Meetings (JSM), Griffith convened a session of the TRB Statistical Methodology and Statistical Computer Software in Transportation Research group, further highlighting the overlap between the two professional communities.
As a longstanding member of the ASA and Project Director of the BTS Research Grants Program, Promod Chandhok, PhD, recognized the need for a dedicated ASA forum where statisticians could engage with transportation issues. His vision was twofold: to bring statisticians into closer contact with the pressing problems of the transportation discipline, and to expose transportation professionals to the breadth of statistical methods available to them.
This dual engagement led directly to the founding of TSIG in 2001, with Chandhok serving as its first Chair. By attending both the January TRB meetings and the August JSM—and subsequently participating in all TRB and JSM thereafter—Chandhok laid the groundwork for a sustained bridge between ASA and TRB. His later membership in the TRB Statistical Methodology and Statistical Computer Software in Transportation Research Committee further reinforced this connection.
The collaboration ensured that TSIG was not an isolated interest group but part of a larger ecosystem, drawing energy from TRB’s applied focus while contributing back methodological depth. Over time, this synergy helped solidify transportation statistics as a legitimate and growing subfield, with TSIG serving as the ASA home for those who straddled both worlds.
From its collaborations with TRB committees, TSIG carried its methodological momentum into the BTS Research Grants Program, where that expertise translated into funded innovation and broader community impact.
TSIG and the BTS Research Grants Program
The BTS Research Grants Program expanded the field well beyond its early emphasis on safety data. Under the direction of Promod Chandhok, PhD, Project Director of the program, the initiative funded projects on visualizing transportation flows, mapping spatial patterns of activity, developing indicators that linked transportation to the broader economy, and producing reliable estimates for smaller geographic areas by integrating multiple data sources. This broadened agenda positioned transportation statistics as a multidimensional enterprise with direct policy relevance.
The grants provided targeted support to academic and research institutions, serving as both a catalyst and a proving ground for innovative methods. Funded projects advanced Bayesian modeling of crash risk, small-area estimation tailored to transportation data, and GIS-based analysis of non-motorized travel behavior. By incorporating multimodal data integration and performance metrics, the program strengthened the connection between methodological development and operational decision making, raising the profile of transportation statistics within the broader statistical community.
TSIG benefited directly from this surge of activity. Grant recipients became active contributors to TSIG sessions at major statistical meetings, presenting work that bridged academic theory and practice. The program encouraged collaboration between statisticians and transportation engineers—a multidisciplinary ethos that TSIG embraced and amplified through its programming, discussion forums, and mentoring of emerging scholars.
One of the program’s most visible achievements was the creation of the Transportation Services Index (TSI) in 2003, a composite measure of freight and passenger movements that soon proved its value as a leading economic indicator. The TSI demonstrated the feasibility of building robust, policy-relevant indices from transportation data and inspired the development of additional measures. TSIG highlighted the TSI in its sessions at the Joint Statistical Meetings and TRB, using it as an example of how innovative statistical tools could transform transportation data into policy insights.
Other projects, such as a metropolitan-level hazmat vulnerability study that combined layered GIS mapping with risk quantification, illustrated how statistical analysis could inform national security and urban planning. These high-consequence applications expanded TSIG’s thematic range and attracted new members.
Beyond individual awards, the grants program legitimized transportation statistics as a distinct subfield. By supporting high-quality proposals across institutions and regions, BTS cultivated a network of researchers whose work flowed naturally into TSIG’s meetings, newsletters, and collaborative efforts. In effect, the program—directed by Chandhok at BTS—laid the empirical and intellectual foundation upon which TSIG built its identity, expanded its membership, and sharpened its contributions to the statistical profession.
TSIG and the Academic Community
The academic community played a foundational role in the growth of the TSIG, with the Department of Statistics at George Washington University (GWU) serving as a key anchor. When Promod Chandhok, PhD, joined BTS in 2000, he began incorporating transportation survey examples into a two semester graduate level course in sampling theory. These real world applications stimulated interest among students and faculty in the emerging field of transportation statistics.
GWU faculty further contributed by reviewing research grant proposals and embedding transportation themes into academic discourse. The integration of transportation into the classroom proved influential: it deepened students’ appreciation of applied statistics and mobilized both faculty and students to support the petition for a new ASA section devoted to transportation statistics. Teaching thus became a catalyst for professional advocacy, linking academic training with institutional development.
Building on this foundation, TSIG cultivated relationships with universities nationwide, encouraging graduate students to present papers, participate in competitions, and engage with federal data resources. These academic connections ensured that TSIG functioned not only as a professional network but also as a pipeline for training and innovation.
Several faculty members illustrate the academic community’s sustained contributions to TSIG. Linda Boyle, PhD, joined TSIG while on the faculty at the University of Iowa. She continued her involvement after moving to the University of Washington, where she organized sessions and presented research that broadened TSIG’s intellectual scope. Now a professor at New York University, Boyle’s career trajectory demonstrates how TSIG’s influence extended as members carried their expertise across institutions.
Feng Guo, PhD, joined TSIG in 2007 while at Virginia Tech, where he has remained throughout his career. His contributions in organizing sessions, presenting research, and mentoring students reinforced TSIG’s role as a bridge between academic training and applied transportation research.
Cliff Spiegelman, PhD, faculty at Texas A&M University and senior scientist at the Texas A&M Transportation Institute, was likewise an active participant. He helped broaden TSIG’s membership and strengthen its academic and applied reach.
Roya Amjadi, of the Federal Highway Administration, also contributed to TSIG’s development. Her active participation in sessions reflected the group’s ability to draw in federal researchers and connect applied practice with the broader statistical community.
Mike Cohen, PhD, provided continuity across TSIG’s history. At BTS until 2006, and later as a consultant and part time faculty member at George Mason University, he attended every TSIG session, serving at times as discussant and chair. His steady involvement ensured that TSIG’s programming remained rigorous and relevant, embodying the dedication of members who sustained the group over decades.
In this way, the academic community—and GWU in particular—provided both the intellectual foundation and grassroots support that allowed TSIG to flourish. By bridging classroom learning with professional advocacy, these contributions reinforced TSIG’s mission to advance methodological rigor, foster interdisciplinary collaboration, and strengthen the role of statistics in transportation research and policy. The academic community’s contributions not only deepened the methodological foundations of transportation statistics but also created the intellectual momentum that would soon be harnessed in large scale federal initiatives such as SHRP II.
TSIG and the Strategic Highway Research Program II (SHRP II)
The Strategic Highway Research Program II (SHRP II), administered by the TRB marked a pivotal moment in transportation safety research. Its Safety track, anchored by the Naturalistic Driving Study (NDS), produced one of the most extensive behavioral datasets ever assembled—capturing over 5.8 million trips and 1.4 million hours of driving across thousands of instrumented vehicles. This unprecedented volume of real world data opened new frontiers for understanding driver behavior, risk factors, and roadway performance.
TSIG established a meaningful connection to SHRP II through the participation of Promod Chandhok serving on the Safety Expert Task Group (ETG) for Project S08. Chandhok provided statistical guidance throughout the project’s lifecycle—from shaping the request for proposals to reviewing submissions and commenting on final deliverables. His involvement ensured that statistical rigor and methodological innovation were embedded in the project’s design and execution, reinforcing TSIG’s commitment to evidence based research and interdisciplinary collaboration.
By maintaining active participation in TRB and Joint Statistical Meetings alongside his SHRP II role, Chandhok positioned TSIG at the intersection of methodological development and applied safety research. This sustained engagement demonstrated how a professional interest group could influence the trajectory of a national research program.
In retrospect, the relationship between TSIG and SHRP II exemplifies how strategic engagement in high impact research can elevate both a professional community and a field of study. Through Chandhok’s sustained involvement, TSIG helped shape the analytical landscape of one of the most ambitious safety initiatives in transportation history, solidifying its role as a vital contributor to the future of transportation statistics.
TSIG’s Legacy and Future Relevance
By December 2011, the TSIG had grown into a vibrant community of more than 200 members. Of these, approximately 120 were ASA members who formally endorsed a petition to elevate the group into a full ASA section. Each supporter sent an email affirming: “I, [name], support the petition to form a new ASA section to be called the Section on Transportation Statistics.” This collective action reflected both the depth of commitment within the community and the recognition that transportation statistics had matured into a distinct and sustainable field within the profession.
With this milestone reached and a draft charter prepared, the management team invited Peg Young, PhD, to lead the next phase. After careful consideration, however, the leadership chose not to pursue the transition. While this decision meant that TSIG remained an interest group rather than becoming a formal section, it did not diminish the group’s influence. On the contrary, the petition process underscored the strength of the community, the breadth of its membership, and the legitimacy of transportation statistics as a professional domain.
TSIG’s legacy lies in the professional home it created for statisticians working in transportation, the collaborations it fostered across disciplines, and the methodological innovations it encouraged. Its ties to TRB, the BTS Research Grants Program, SHRP II, and the academic community ensured that transportation statistics was both rigorous and relevant. In this way, TSIG’s story is not only a record of what has been accomplished but also a foundation for what remains to be done. Its legacy is one of persistence, innovation, and bridge building—a reminder that even without formal section status, the group left an indelible mark on ASA and the transportation research community—one that continues to shape the field today.
Epilogue: TSIG in the Broader ASA Landscape
TSIG’s history illustrates the broader role of interest groups within ASA. The association’s structure has long provided a pathway for emerging fields to gain visibility, test their staying power, and, in some cases, transition into full sections. TSIG followed this trajectory—building momentum through collaborations with TRB, federal research programs, and academic institutions, and advancing to the point of a formal petition for section status.
In the broader ASA landscape, TSIG stands as a reminder that interest groups can be incubators of innovation, catalysts for collaboration, and guardians of professional identity. Its story is not only a chapter in ASA’s institutional history but also a testament to the enduring power of statisticians to shape how society understands and improves transportation systems.
Closing Note: This account of the Transportation Statistics Interest Group is offered as a record for the profession and a guide for the future. It preserves the voices, milestones, and bridges that defined TSIG, ensuring that its contributions remain part of ASA’s living history.
Author: Promod K. Chandhok