Construction safety has traditionally been managed with lagging measures such as recordable injury rates, which can only trigger responses after harm has occurred. Hallowell, Hinze, Baud and Wehle (2013) codified a proactive alternative: 13 measurable safety leading indicators — including near-miss reporting, safety observation programs, pretask planning, auditing, housekeeping rubrics, and owner participation — each with a measurement definition (mostly normalized per 200,000 worker-hours), required resources, and predefined management responses. The indicators were promoted on the basis of expert panel judgment and award-winning-project practice in large U.S. firms, not on longitudinal statistical evidence, and prescriptive numeric target thresholds were not supplied. The open problem is to turn this expert-promoted set into an empirically validated and deployable system of project safety control: field-test and longitudinally validate each indicator's predictive relationship to future safety performance and the causal injury-reduction effect of implementing the program, develop empirically justified threshold-setting procedures calibrated to organizational safety maturity, establish reliable measurement rubrics for the qualitative indicators, and demonstrate validity and practical integration beyond the original large-U.S.-firm sample. A decade of follow-up work has produced predictive models in the adjacent oil-and-gas sector, meta-analytic correlations, time-series evidence that indicator activities both lead and lag injury rates, and implementation frameworks, but the construction-specific longitudinal causal validation, threshold calibration, and rubric psychometrics remain unachieved, and systematic reviews through 2024–2026 still identify indicator effectiveness as unresolved.

Background

In construction project management, safety performance has historically been measured with lagging indicators — outcome counts recorded after the fact, such as the Total Recordable Injury Rate (TRIR, the number of recordable injuries per 200,000 worker-hours of exposure) — so management action is triggered by harm that has already occurred. A leading indicator, by contrast, is a measurable safety-related practice or condition (for example the rate of near-miss reports, the share of tasks with pretask plans, or the percentage of audited items in compliance) that is monitored during construction and used to trigger corrective action before an injury happens. The idea parallels proactive cost and schedule control: measure a process variable on a time series, compare it with a target, and execute a predefined response when it deviates. Related but distinct constructs include safety climate (workers' shared perceptions of the priority of safety, usually measured by survey) and precursor analysis (identification of worker- or crew-level conditions that precede severe events); a leading-indicator program instead tracks the quantity and quality of safety management activities, normalized to exposure.

Hallowell, Hinze, Baud and Wehle (2013) report a mixed-methods study — comparative case studies, content analysis of 14 award-winning construction projects from two large companies, and expert-panel deliberation — that generated more than 50 candidate proactive metrics and promoted 13 as high-priority leading indicators. For each promoted indicator the paper provides an operational definition (e.g., a 3-month moving average of near misses or safety observations per 200,000 worker-hours; percentage of audited items in compliance; rubric-based scores for housekeeping and pretask-plan quality), the resources needed to measure and trend it, and the management responses to execute when the indicator falls below a desired value. Two limitations of this evidence base stand out. First, the evidence connecting the indicators to safety outcomes was indirect: the indicators were promoted by expert judgment and their use was observed in industry-leading organizations, without statistical demonstration that each indicator predicts future performance or that implementing the program causes fewer injuries. Second, prescriptive numeric thresholds were not supplied — appropriate target values depend on an organization's existing safety maturity (the sophistication of its safety management system and culture) — while the underlying sample was concentrated on large U.S. firms affiliated with the Construction Industry Institute (CII) and the Associated General Contractors of America (AGC).

The problem statement below asks for the empirical and methodological program that converts this promoted indicator set into a validated, calibrated, and routinely deployable safety-control system. Subsequent literature has only partially advanced these needs.

Problem Statement

The overarching objective is to convert the set of 13 construction safety leading indicators promoted by Hallowell, Hinze, Baud and Wehle (2013) — each with its published measurement definition, resource requirement, and predefined management response — into an empirically validated, threshold-calibrated, and routinely deployable system of proactive safety control for construction projects. Within that single objective, five scientifically linked questions remain to be answered: (1) Field testing and longitudinal validation of the promoted leading indicators — for each indicator, establish from longitudinal multi-project field data the extent to which it predicts future safety performance (with an analysis that accounts for the feedback by which past injury rates also drive indicator activity), and determine whether implementing the indicator program causally reduces injuries, using a design that can support causal inference rather than mere association. (2) Threshold setting — develop empirically justified procedures that translate an organization's safety maturity (the sophistication of its safety management system and culture) into appropriate numeric target values for each indicator, replacing the absent prescriptive thresholds. (3) External validity — validate the indicators and the implementation protocol outside the original sample of large U.S. CII/AGC-affiliated organizations, across geographic regions, smaller firms, and diverse construction sectors. (4) Measurement quality — refine and test the measurement rubrics for the qualitative indicators (e.g., housekeeping, pretask-plan quality, safety-observation quality) so that they achieve demonstrated interrater reliability (agreement between independent raters) and support trend analysis. (5) Integration — determine how to embed the leading-indicator program into routine project controls and metrics used by owners, contractors, and vendors without creating measurement overload or indicators that fail to lead to improvement. The five questions are interdependent: thresholds and rubrics acquire meaning for indicators whose predictive and causal value has been established, and integration is the deployment endpoint of a validated, calibrated measurement system. Together these five questions define the program this objective requires: it is addressed in full only when all five are answered, and because each is independently researchable, a self-contained treatment of any one of them resolves that question alone while leaving the others open.

References

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