DOT/FRA/ORD-20/15 Final Report

April 2020 

U.S. Department of 

Transportation

Federal Railroad 

Administration

Consistent Trespasser Intent Determination 

Criteria Pilot Project

Office of Research,

Development

and Technology

Washington, DC 20590
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Technical Report October 2014–March

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4. TITLE AND SUBTITLE

Consistent Trespasser Intent Determination Criteria Pilot Project

5. FUNDING NUMBERS

RR04AA 6. AUTHOR(S)

Stephanie G. Chase, PhD, and Danielle Hiltunen

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

Volpe National Transportation Systems Center

55 Broadway

Cambridge, MA 02142

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U.S. Department of Transportation 

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Office of Research, Development and Technology

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DOT/FRA/ORD-20/15

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COR: Starr Kidda, Michael Coplen (formerly) 

12a. DISTRIBUTION/AVAILABILITY STATEMENT

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13. ABSTRACT (Maximum 200 words)

This document describes a pilot project that evaluated the potential for developing standardized criteria that railroads can use to

determine the probable intent (i.e., suicide or accident) of individuals involved in trespasser strikes on railroad right-of-way in 

the United States from October 2014 to March 2020. These criteria are designed to help railroads better understand suicide and 

trespass incidents that occur on the right-of-way, and support the selection and evaluation of mitigation strategies. The John A. 

Volpe National Transportation Systems Center (Volpe) used an approach similar to the criteria implemented by the Railway 

Safety and Standards Board and European Railway Agency and developed a modified version of the “Ovenstone” criteria called 

Trespasser Intent Determination and Evaluation (TIDE). The criteria can assist railroads in making consistent internal judgments 

about the probable intent (i.e., suicide or accident) of an individual involved in a trespasser strike regardless of whether the 

outcome is a fatality or injury. The criteria includes three types of factors that can be used to make one of three determinations: 

probable suicide, probable accident or inconclusive. 

14. SUBJECT TERMS

Suicide, trespass, railroad, countermeasure, fatalities, determination criteria, human factors, pilot 

project

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26 

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NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89) 

Prescribed by ANSI Std. 239-18 

298-102
ii

METRIC/ENGLISH CONVERSION FACTORS

ENGLISH TO METRIC METRIC TO ENGLISH

LENGTH (APPROXIMATE) LENGTH (APPROXIMATE)

1 inch (in) = 2.5 centimeters (cm) 1 millimeter (mm) = 0.04 inch (in) 

1 foot (ft) = 30 centimeters (cm) 1 centimeter (cm) = 0.4 inch (in) 

1 yard (yd) = 0.9 meter (m) 1 meter (m) = 3.3 feet (ft)

1 mile (mi) = 1.6 kilometers (km) 1 meter (m) = 1.1 yards (yd)

1 kilometer (km) = 0.6 mile (mi)

AREA (APPROXIMATE) AREA (APPROXIMATE)

1 square inch (sq in, in2) = 6.5 square centimeters (cm2) 1 square centimeter 

(cm2)

= 0.16 square inch (sq in, in2) 

1 square foot (sq ft, ft2) = 0.09 square meter (m2) 1 square meter (m2) = 1.2 square yards (sq yd, yd2) 

1 square yard (sq yd, yd2) = 0.8 square meter (m2) 1 square kilometer (km2) = 0.4 square mile (sq mi, mi2) 

1 square mile (sq mi, mi2) = 2.6 square kilometers (km2) 10,000 square meters 

(m2

) 

= 1 hectare (ha) = 2.5 acres 

1 acre = 0.4 hectare (he) = 4,000 square meters (m2)

MASS - WEIGHT (APPROXIMATE) MASS - WEIGHT (APPROXIMATE)

1 ounce (oz) = 28 grams (gm) 1 gram (gm) = 0.036 ounce (oz) 

1 pound (lb) = 0.45 kilogram (kg) 1 kilogram (kg) = 2.2 pounds (lb)

1 short ton = 2,000 pounds 

(lb)

= 0.9 tonne (t) 1 tonne (t) =

=

1,000 kilograms (kg) 

1.1 short tons

VOLUME (APPROXIMATE) VOLUME (APPROXIMATE)

1 teaspoon (tsp) = 5 milliliters (ml) 1 milliliter (ml) = 0.03 fluid ounce (fl oz)

1 tablespoon (tbsp) = 15 milliliters (ml) 1 liter (l) = 2.1 pints (pt) 

1 fluid ounce (fl oz) = 30 milliliters (ml) 1 liter (l) = 1.06 quarts (qt)

1 cup (c) = 0.24 liter (l) 1 liter (l) = 0.26 gallon (gal)

1 pint (pt) = 0.47 liter (l) 

1 quart (qt) = 0.96 liter (l) 

1 gallon (gal) = 3.8 liters (l) 

1 cubic foot (cu ft, ft3) = 0.03 cubic meter (m3) 1 cubic meter (m3) = 36 cubic feet (cu ft, ft3)

1 cubic yard (cu yd, yd3) = 0.76 cubic meter (m3) 1 cubic meter (m3) = 1.3 cubic yards (cu yd, yd3)

TEMPERATURE (EXACT) TEMPERATURE (EXACT)

[(x-32)(5/9)] °F = y °C [(9/5) y + 32] °C = x °F

QUICK INCH - CENTIMETER LENGTH CONVERSION

0 1 2 3 4 5

Inches

Centimeters 0 1 2 3 4 5 6 987 1110 1312

QUICK FAHRENHEIT - CELSIUS TEMPERATURE CONVERSIO

°F -40° -22° -4° 14° 32° 50° 68° 86° 104° 122° 140° 158° 176° 194° 212°

 °C -40° -30° -20° -10° 0° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100°

I I I I 

For more exact and or other conversion factors, see NIST Miscellaneous Publication 286, Units of Weights and 

Measures. Price $2.50 SD Catalog No. C13 10286 Updated 6/17/98
iii

Acknowledgements

The authors would like to thank the following for their support and guidance in this project: the 

Federal Railroad Administration’s (FRA) Office of Research, Development and Technology’s

(RD&T) Director, Dr. Maryam Allahyar, Dr. Starr Kidda, Chief of the Human Factors Division 

of FRA’s RD&T, and Michael Coplen, former Program Manager from the FRA RD&T Human 

Factors division. The authors would also like to acknowledge Michael Martino, formerly of the 

Association of American Railroads, for his support of this effort, and the participating railroads 

for their time and valuable contributions. 
iv

Contents

Executive Summary........................................................................................................................ 1

1. Introduction ............................................................................................................................ 3

1.1 Background ................................................................................................................. 3

1.2 Objectives.................................................................................................................... 4

1.3 Overall Approach ........................................................................................................ 5

1.4 Scope ........................................................................................................................... 5

1.5 Organization of the Report .......................................................................................... 5

2. Consistent Trespasser Intent Criteria ..................................................................................... 6

2.1 Development of the Criteria ........................................................................................ 6

2.2 Evaluation of the Criteria ............................................................................................ 7

3. Conclusion ............................................................................................................................. 9

4. References ............................................................................................................................ 11

Appendix A. TIDE Criteria for Railroads in the United States (Version I) and Decision Tree ... 12

Abbreviations and Acronyms ....................................................................................................... 19
v 

Illustrations

Figure 1: Logic Model for Determination of Intent Project ........................................................... 5

Figure 2. TIDE Flowchart ............................................................................................................. 18
1 

Executive Summary

This report describes a pilot project evaluating the potential for developing standardized criteria 

for railroads to determine the probable intent (i.e., suicide or accident) of individuals involved in 

trespasser strikes on railroad right-of-way in the US, in support of the Federal Railroad 

Administration (FRA). In 2014, the John A. Volpe National Transportation Systems Center 

(Volpe) developed and began evaluating a modified version of the “Ovenstone” criteria, referred 

to as the Trespasser Intent Determination and Evaluation (TIDE) criteria, which used an 

approach similar to the criteria implemented by the Railway Safety and Standards Board (RSSB) 

(RSSB, 2015) and European Railway Agency (ERA) (ERA, 2013). 

The TIDE criteria can be used to make consistent secondary judgments about the intent (i.e., 

suicide or accident) of an individual involved in a trespasser strike regardless of whether the 

outcome is a fatality or injury. Volpe’s modification was necessary in order to account for the 

availability of past and current mental health information due to regulations about the privacy of 

health information in the US. The TIDE criteria are intended to be used internally at railroads, 

and will not supersede official manner of death determinations made by a coroner or medical 

examiner.

The TIDE criteria consider the following types of information: 

Direct Factors: This is the evidence that, on its own, can be used to determine if a suicide is 

probable. 

Modifying Behaviors: This is evidence of behaviors, including eye contact and the direction 

the individual was facing, that can be used with other evidence to suspect probable suicidal 

intent. This information may be helpful in modifying determinations that are not already 

conclusive based on the direct evidence section. 

Inconclusive Factors: When the information—or lack of information—about a particular 

incident does not provide evidence in accordance with the factors above, or there is an 

indication of drug or alcohol use without direct factors. 

From the factors described above, one of three determinations of intent can be made: 

Probable Suicide: The individual’s actions were intentional—they intended to harm 

themselves. 

Probable Accident: The individual’s actions were unintentional—they did not intend to 

harm themselves. 

Inconclusive: Insufficient information to determine probable intent of the individual. 

To evaluate the TIDE criteria, the following steps should occur: 

Step 1: Resource Availability. Information is collected by the railroads and it is used to

create determination criteria for the individual’s intent, which will be evaluated for both 

reliability and validity. Volpe is currently partnered with two railroads, each in a different 

geographical region of the US. 

Step 2: Development and Refinement. In this step, preliminary categories were created, the 

information collected from railroads was coded using TIDE, and the coding process was 

documented. A sample of those reports was selected to assess inter-rater reliability. This 
2 

process generated several iterations of the criteria. After any disagreements over intent 

determinations were resolved, researchers reported the process and findings to each 

individual railroad for stakeholder feedback to further refine the criteria. Ongoing data 

collection is also occurring for both railroads. 

Step 3: Greater Stakeholder Involvement. The team is currently working to increase 

stakeholder involvement, and facilitate partnerships with additional railroads to better 

evaluate the TIDE criteria at different locations and types of railroads across the US. 

Step 4: Evaluation – Usefulness of the TIDE Criteria. Finally, the last evaluation step is a

long-term effort that will focus on mitigations that were proposed and implemented using 

knowledge gained by the TIDE criteria. This step is expected to include data analysis based 

on the incident reports and determinations made using the TIDE criteria. This will also 

provide an opportunity to further refine the criteria and implement a guidance and 

recommendation document for the criteria that can be made easily available to all railroads 

who wish to use this tool.
3 

1. Introduction

The Federal Railroad Administration (FRA) is interested in learning more about the trespasser

strikes on the US rail system that occur due to suicide attempts. Over the past several years, FRA

has provided funding to the John A. Volpe National Transportation Systems Center (Volpe) to

investigate this topic. While Volpe continues to advance the state of knowledge surrounding rail 

suicide and suicide attempts in the US, there is a need to better understand the factors involved in 

making determinations that explain the intent of these individuals, and assist railroads in

selecting and evaluating potential mitigation strategies to reduce the number of suicides on the 

rail system.

This document discusses a pilot project that evaluates the potential for developing standardized 

criteria for railroads to internally determine the probable intent (i.e., suicide or accident) of 

individuals involved in trespasser strikes on railroad right-of-way in the US that took place from 

October 2014 to March 2020. 

1.1 Background 

Rail suicide data collection is mandated by the Code of Federal Regulations (CFR) and the data 

is currently collected by FRA. This topic is also covered by FRA’s Guide for Preparing 

Accident/Incident Reports (FRA, 2011). When a trespasser strike results in a fatality, a coroner 

or medical examiner conducts an investigation to determine the official manner of death (i.e., 

suicide, accident, undetermined, etc.) When a trespasser strike results in an injury, there is no 

investigation by a medical examiner or coroner. Therefore, a determination about a suicide 

attempt (injury), is only documented if relevant information is available. This may largely 

depend on the individual’s willingness to disclose this information to authorities or rail staff 

present at the scene. 

Determinations about intent may be inconsistent depending on whether a fatality or injury is 

ruled a suicide or accident, and the number of suicides and suicide attempts may be 

underreported. Past research examining international suicide statistics supports the potential for 

underreporting (Reynders, Scheerder, and Van Audenhove, 2010; Tøllefsen, Hem, and Ekeberg, 

2012). This inconsistency in determinations could negatively affect efforts to identify trends that 

exist in rail suicide and trespass data and to evaluate the true impact of mitigation strategies. 

Given the challenges associated with consistently reporting railroad suicide incidents, Volpe 

explored a secondary method for determining probable intent of the individual (i.e., suicide or 

accident) for internal use within railroads. This approach is not unprecedented. In 1994, 

Symonds re-categorized rail fatalities and injuries using a checklist of eight criteria to suspect 

probable suicides. The Railway Safety and Standards Board (RSSB) in the United Kingdom 

(UK) has taken a similar approach, allowing railroads to make preliminary determinations about 

an individual’s intent and suspect suicide using the “Ovenstone” criteria, which has been tailored 

for railways (RSSB, 2015). The European Railway Agency (ERA) also allows member States to 

use an adapted set of “Ovenstone” criteria to classify incidents and suspect suicide where the 

official manner of death is undetermined (ERA, 2013). The “Ovenstone” criteria identifies 

common factors involved in suicides and suicide attempts based on mental health diagnoses, 

previous indication of intent, patterns of suicidal behavior, and reactions to stressful situations 

(Ovenstone, 1973). Modified versions of this criteria may also account for the individual’s 

actions and behaviors preceding and at the time of the incident. 
4 

Using an additional method for determining intent will not supersede the official manner of 

death; however, this method for secondary determination may give railroads a streamlined 

mechanism in understanding suicide and trespass incidents that are occurring on their tracks. A 

secondary determination has three advantages: 

• The determination of intent can be made quickly after an incident occurs. 

• The determination is standardized for each incident and provides consistency and 

reliability in the determinations made within and between railroads. 

• A probable determination of intent can be made for incidents resulting in a fatality and

injury. This can provide railroads with a more accurate and comprehensive representation 

of the incidents occurring on their tracks and help to select and evaluate mitigation 

strategies.

Criteria that are based on internal determinations have the potential to give railroads a timely and 

comprehensive understanding of possible trends of trespasser strikes within their rail system. 

This can be especially important when multiple incidents occur in a short duration (e.g., a 

copycat or hotspot situation). Although Volpe partnered with two railroads for this effort, the 

potential to partner with additional railroads from a greater breadth of regions within the US is 

being explored. Collecting additional information will lead to a more comprehensive 

understanding of primary factors that can be considered within each incident when mitigation 

efforts are proposed; therefore, the impact of these efforts to stakeholders is projected to be 

greater.

1.2 Objectives

This pilot project evaluated the potential for developing standardized criteria for railroads to 

determine the probable intent (i.e., suicide or accident) of individuals involved in trespasser 

strikes on railroad right-of-way in the US. The criteria should be used internally to help railroads 

better understand suicide and trespass incidents that occur on the right-of-way, and support the 

selection and evaluation of mitigation strategies.

Figure 1 is a visual representation of the logic model for the Determination of Intent research 

project, which provides a better understanding of the project’s goals and presumed impact to 

stakeholders and the community’s safety. For this specific project, some of the activities and 

outputs share the same outcome and in a few cases the outcomes share the same potential impact 

(see Figure 1). It is believed that the outcomes of this project will affect the level of safety in 

railroad operations—in terms of trespasser fatalities—and it will also provide better quality data 

for future risk assessments and migration efforts along the railroad right-of-way.
5 

Figure 1: Logic Model for Determination of Intent Project

1.3 Overall Approach

The approach of this evaluation is to examine the potential for a secondary determination about 

the intent (i.e., suicidal or accidental) of individuals involved in fatal and non-fatal trespasser 

strikes on US right-of-way and identify lessons learned. The criteria are based on an approach 

that has been used in countries outside of the United States (i.e., Australia, Sweden, and the UK), 

and modified to account for differences in the availability of certain types of information. 

Researchers compared the official manner of death determinations made by a coroner or medical 

examiner with supplemental intent determinations using the TIDE criteria. Researchers also 

explored the utility of TIDE criteria to understand the suicide and trespass incidents, improve 

data collection, and select and evaluate mitigation strategies.

1.4 Scope

This evaluation considered a total of 9 years of incident data from two railroads in different 

regions of the US. 

1.5 Organization of the Report

This report is separated into the following three sections: 

Section 1: Introduces the background and objectives of the project, overall approach, and scope. 

Section 2: Describes the development and evaluation process of the pilot project. 

Section 3: Provides concluding information regarding lessons learned and next steps. 
6 

2. Consistent Trespasser Intent Criteria

2.1 Development of the Criteria

To create the criteria, Volpe partnered with two railroad carriers in different geographical regions 

of the US. Both railroads provided access to their trespasser strike incident report data—that 

result in injury or death—which can include several documents such as: 

• Police reports

• Death certificates (as applicable)

• Witness statements

• Railroad Equipment Accident/Incident Report (FRA F 6180.54) 

• FRA Injury and Illness Summary (FRA F 6180.55) 

• Highway-Rail Grade Crossing Accident/Incident Report (FRA F 6180.57) 

To better fit the availability of information in the US, Volpe created a modified version of the 

death determination “Ovenstone” criteria currently used by the RSSB in the UK. The UK and US 

have different health privacy laws, which means that information about an individual’s mental 

health history, including previous suicide attempts, is most likely not available in the US. 

Therefore, Volpe created multiple iterations of the “Ovenstone” criteria that do not rely on an 

individual’s past mental health history. Additionally, the determination criteria were broadened 

to include the determinations of incidents that led to an injury as well as death.

Railroad employees stated that suicide attempts (i.e., non-fatal) can also be traumatic to railroad 

employees and should be included in any impact assessments. Additionally, many incidents each 

year result in injuries and a portion of those incidents may show that there was intent to selfharm. Non-fatal attempts were considered an important inclusion for railroads, so specific

locations can be identified where incidents involving intentional acts to harm oneself occur 

regardless of outcome (i.e., injury or death). 

Volpe’s TIDE criteria included the following three types of factors based on the information 

provided on each incident (see Appendix A for the complete criteria): 

Direct Factors: Information that, on its own, can determine if a suicide is probable. For 

example, suicide notes, statements of intent, and specific wording in an incident report alone 

can be used as sufficient criteria to suspect probable suicidal intent.

Modifying Behaviors: Information about behaviors, including eye contact and the direction 

the individual was facing, that can be used with other evidence to suspect probable suicidal 

intent or a probable accident. Other examples include whether the individual was seen at the 

location prior to the incident, was distracted wearing headphones, if visual or aural warnings 

were present, depression or withdrawal noted by others, or marked emotional response to 

recent events.

Inconclusive Factors: When the information—or lack of information—about a particular 

incident is insufficient to make a determination, an inconclusive determination is given. This 

category also includes evidence of alcohol or drugs at the time of the incident without any 
7 

direct evidence that would allow a determination to be made (such as a suicide note). 

Otherwise the individual’s intent cannot be determined due to the drug(s) in their system. 

From these categories of information, one of three determinations of intent (regardless of 

physical outcome—fatal or injury) can be made: 

Probable Suicide: The individual’s actions were likely intentional—they intended to harm 

themselves. 

Probable Accident: The individual’s actions were likely unintentional—they did not intend 

to harm themselves. 

Inconclusive: Insufficient information to determine probable intent of the individual. 

2.2 Evaluation of the Criteria

Four steps were taken to evaluate how the TIDE criteria would assist the railroads select and 

evaluate suicide mitigation strategies on the right-of-way.

Step 1: Resource Availability. The first step was to understand what information is collected by 

the railroads and create criteria for identifying the probable intent of the individual that could be 

evaluated for both reliability and validity. The team looked through the data provided and placed 

the information into high level categories such as incident location, demographics of the 

decedent/individual, and environmental factors. From these categories, the team created 

subcategories and tracked how often each subcategory was used, as well as how detailed each 

subcategory became. This process helped formulate the basis for understanding factors involved 

in the trespasser strike incident that could possibly be used to differentiate an individual’s intent; 

or a suicide from a trespass (accidental) incident.

Step 2: Development and Refinement. After creating the categories, two individual coders 

independently examined 1 year of trespasser strike incident report data from each railroad. These 

coders recorded essential information about the incident, and then they were asked to decide if 

the incident was a probable accident, a probable suicide or there was inconclusive evidence. 

Finally, the coders recorded what categories of information they used and its order of importance 

in their determination.

After all incident determinations were completed by each coder, a third party talked to each 

coder and recorded the process that they used to determine intent. Consistencies and 

disagreements between both coders’ processes were documented so the team could better 

understand which information carried more weight when a determination was made. When the 

two coders did not make the same determination, we also brought in a third coder to see if a 

majority determination could be found. An additional coder completed a random selection of 20 

percent of incidents for inter-rater reliability purposes, and the third coder’s process was 

documented as well.

The initial assessment process became the basis for the preliminary TIDE criteria, which 

researchers used to make secondary intent determinations about past trespasser strikes. As 

researchers analyzed the report data, the TIDE criteria was refined once more to its current form 

and all incident data received was recorded. After any disagreements with determinations were 

discussed, researchers reported the process and findings to each individual railroad for 

stakeholder feedback. Although both railroads have expressed positive responses about these

efforts, detailed feedback was not received to date. 
8 

For both railroads, ongoing data collection is occurring. As the number of incidents available to 

us increases, the ability to generalize from the current findings widens. Volpe will continue the 

process of documenting and updating the TIDE criteria as deemed necessary.

To date, researchers identified two main outcomes when the official determination is compared 

to the TIDE criteria. First, a higher number of probable suicide attempts (injuries) resulted when 

using TIDE. Second, TIDE resulted in fewer incidents that were officially determined to be fatal 

accidents, and a higher number of inconclusive determinations. This is due to the lack of 

information available in the incident reports. This finding highlights the need for more detailed, 

high quality data that is consistently collected for both fatalities and injuries.

Step 3: Greater Stakeholder Involvement. In this step, the team will pursue greater

stakeholder involvement by facilitating partnerships with additional railroads to better evaluate 

the TIDE criteria at different locations and types of railroads across the US.

Step 4: Evaluation – Usefulness of the TIDE Criteria. This step will be a long-term evaluation 

effort that is planned over a period of time, as mitigation efforts are being proposed and 

implemented with the knowledge gained by the TIDE criteria. The goal of this extended 

evaluation is to determine whether consistent trespasser intent criteria could be successfully 

implemented by the railroads themselves. It will also determine whether the TIDE criteria 

allowed railroads to better understand trespass and suicide on the right-of way, helped them to 

select and evaluate mitigations, as well as identify any barriers that may arise and propose 

solutions. This evaluation will examine the number of trespasser strikes that are mitigated in a 

specific location determined by these criteria and look at any additional uses the railroad has 

found for this information. Step 4 will also give the team an opportunity to refine the criteria and 

implement a guidance document for using the criteria, which would be made available to all 

interested railroads. This tool could also be provided to railroads using Volpe’s webpage, Rail 

Suicide Prevention Resource Page, developed for the suicide and trespass prevention work that is 

sponsored by FRA and conducted at Volpe. 
9 

3. Conclusion

From October 2014 to March 2020, this project evaluated the potential for developing 

standardized criteria that allow railroads to determine the probable intent (i.e., suicide or 

accident) of individuals involved in trespasser strikes on railroad right-of-way in the US. Volpe 

took an approach similar to the RSSB and ERA and developed a modified version of the 

“Ovenstone” criteria, named the TIDE criteria, that allows railroads to make consistent 

judgments about the intent (i.e., suicide or accident) of an individual involved in a trespasser 

strike regardless of whether the outcome is a fatality or injury. The criteria would be used 

internally to help railroads better understand suicide and trespass incidents that occur on the 

right-of-way and assist them in selecting and evaluating mitigation strategies. TIDE is not 

intended to supersede the official manner of death determined by a coroner or medical examiner. 

The TIDE criteria include the following types of information: 

Direct Factors: Information that, on its own, can be used to determine if suicidal intent is 

probable. 

Modifying Behaviors: Recorded behaviors that can be used with other evidence to suspect 

probable suicidal intent.

Inconclusive Factors: When the information—or lack of information—about a particular 

incident does not provide evidence in accordance with the categories above. 

From the four categories described above, one of three determinations of intent can be made:

Probable Suicide: The individual’s actions were intentional—they intended to harm 

themselves. 

Probable Accident: The individual’s actions were unintentional—they did not mean to harm 

themselves. 

Inconclusive: There was insufficient information to determine probable intent of the 

individual. 

To date, two railroads have partnered with Volpe in the pilot project. As of March 2020, two of 

the four evaluation steps identified by this document were completed: 1) understanding the 

information available to railroads when a trespasser strike occurs, and 2) developing and refining 

the preliminary TIDE criteria. Evaluation findings reveal that TIDE criteria can provide the most 

benefit to railroads with more detailed data that is consistently collected for both trespass 

fatalities and injuries. High quality data can be facilitated by using the components of the TIDE 

criteria to guide data collection after a strike occurs.

The third step in the evaluation process is underway as of March 2020. In the third step, 

researchers will pursue greater involvement by stakeholders, and facilitate partnerships with 

additional railroads to better evaluate the TIDE criteria at different locations across the US at 

different types of railroads.

In the fourth step, the team will develop an evaluation plan that determines: 

• Whether a consistent trespasser intent criteria can be successfully implemented within the

context of the railroads themselves
10 

• Whether the TIDE criteria was able to address the needs of the railroads in better 

understanding trespass and suicide on the right-of way

• Whether the criteria helped railroads select and evaluate mitigations

Any barriers that may arise will also be identified, and potential solutions will be proposed. The 

fourth step should include data analysis based on the incident data and determinations made 

using the TIDE criteria, and additional interviews to identify other uses for the TIDE criteria 

found by the railroads. This also provides an opportunity to further refine the criteria and 

implement a recommended usage document that can be made easily available to all railroads 

interested in this tool.
11 

4. References

European Railway Agency (ERA). (2013). Implementation Guidance for CSIs, Annex 1 of 

Directive 2004/49/EC As Amended by Directive 2009/149/EC. (ERA/GUI/09-2013).

Federal Railroad Administration (FRA). (2011). FRA Guide for Preparing Accident/Incident 

Reports. 

Ovenstone, I. M. (1973). Spectrum of Suicidal Behaviours in Edinburgh. British Journal of 

Preventive & Social Medicine, 27(1), 27–35. 

Railway Safety and Standards Board (RSSB). (2015). Annual Safety Performance Report 2014/15: 

A Reference Guide to Safety Trends on GB Railways. 

Reynders, A., Scheerder, G., and Van Audenhove, C. (2011). The reliability of suicide rates: an 

analysis of railway suicides from two sources in fifteen European countries. Journal of 

Affective Disorders, 131(1), 120–127. 

Symonds, R. L. (1994). Psychiatric and preventative aspects of rail fatalities. Social Science & 

Medicine, 38(3), 431–435. 

Tøllefsen, I. M., Hem, E., & Ekeberg, Ø. (2012). The reliability of suicide statistics: a systematic 

review. BMC Psychiatry, 12(1), 1. 
12 

Appendix A. 

TIDE Criteria for Railroads in the United States (Version I) and 

Decision Tree

I. Direct Factors: These are factors that can be used to determine if a suicide is probable. For 

example, suicide notes, statements of intent, or specific wording in incident reports alone can be 

used as sufficient criteria to suspect probable suicidal intent.

Presence of a suicide note: Was a suicide note mentioned in the report? If yes, then a 

determination of probable suicide can be made on this evidence alone. If explicitly stated that no 

note was found, indicate no. Otherwise indicate not mentioned. If no note is found or mentioned 

in the report, it has no bearing on the determination of suicide. 

1 = Yes

2 = No

3 = Not mentioned 

Prior statement of suicidal intent or suicide attempt: Does the report contain information 

from an individual who heard the individual express intent for self-harm preceding the incident? 

Alternatively, was there any other indication that the individual had expressed suicidal intent 

(e.g., a post on social media or statements to family/friends in the day(s) preceding)? If yes, then 

a determination of probable suicide or suicide attempt can be made on this information alone. If 

explicitly stated that no statement of intent was reported, indicate no. Otherwise indicate not 

mentioned. If no statement of intent or such a statement is not mentioned in the report, this has 

no bearing on the determination of suicide. 

1 = Yes

2 = No

3 = Not mentioned 

Behavior demonstrates suicidal intent: What specific action(s) were taken by the individual in 

the moments preceding the impact with the train? This section only includes the direct action that 

was taken by the person without considering other informative details about where they were 

looking, etc. If an action with an asterisk is included in the description, then no additional 

modifying behaviors are needed to suspect probable a probable suicide or suicide attempt. 

Choose one or more behaviors in the chronological order they are described in report (e.g., 4, 3, 

2). Describe other behaviors preceding the incident that are known, for example, pacing, 

allowing multiple trains to pass, visible agitation, leaving personal items behind, etc. 

1 = Lying on track

2 = Kneeling inside gauge 

3 = Sitting on tracks 

4 = Standing on tracks 

5 = Walking along track inside gauge) 

6 = Walking along tracks (outside gauge) 
13 

7 = Walking across tracks

8 = Running along tracks (inside gauge) 

9 = Running along tracks (outside gauge) 

10 = Running across tracks 

11 = Jumped in front of train at the last minute*

12 = Clear attempt to avoid train

13 = Stuck on tracks 

14 = Retrieving object from tracks 

15 = On/in vehicle (in motion) 

16 = On/In vehicle (not in motion) 

17 = Other behavior (specify)

Wording in report information: Was language used that directly states the act was a suicide, 

suicide attempt, or accident? Examples may include the word suicide, intentional, deliberate, 

etc., or the report may explicitly describe that the individual was attempting to beat the train, 

play chicken, tripped, fell, etc. If language described intent, then a determination of probable 

suicide or accident can be made on this information alone. Otherwise indicate not mentioned. If 

such a statement is not mentioned in the report, this has no bearing on the determination. 

1 = Yes – Intentional/suicidal wording

2 = Yes – Unintentional/accident wording

3 = Not mentioned 

II. Modifying Behaviors: This is evidence of behaviors, including eye contact and direction the 

individual was facing, that can also be used with other evidence to suspect probable suicide. The 

information in this section may be helpful in modifying determinations that are not already 

conclusive based on the Direct Factors section. None of the information in this section on its 

own is sufficient to suspect probable suicide. However, it may modify the information included 

in the direct modifying behaviors listed above so that a probable suicide or suicide attempt may 

be suspected. In some cases, when the individual is in a vehicle behavioral information can be 

difficult to obtain. In these cases please indicate that this is not-applicable and the reason why. 

Direction Looking: What direction was the individual facing prior to impact? This information 

should be considered in conjunction with the information about behavior (under Direct Factors) 

to determine if the individual was likely to have been attempting suicide. For example, an 

individual facing a train but failing to attempt to move may indicate intent. Alternatively, an 

individual facing away from a train, but not attempting to move may indicate that they were 

unaware of the approaching train.

Choose all actions described in order they are included within report (e.g., X, X, X): 

1 = At/toward train

2 = Away from train

3 = Perpendicular to train
14 

4 = Not mentioned 

5 = Not applicable (specify): ______ 

Eye contact: Did the individual make eye contact with the driver of the train prior to impact? If 

the individual made eye contact with the driver and did not make an attempt to remove 

him/herself from the right-of-way, this is a strong indication of a probable suicide or suicide 

attempt. If the report states that the individual was facing away from the train the coding 

response would be no. If there isn’t any mention regarding eye contact indicate not mentioned. 

If the individual was in a vehicle or other situation where eye contact would not be seen then 

choose not applicable and state the reason why.

1 = Yes

2 = No

3 = Not mentioned 

4 = Not applicable (specify): _______________ 

Auditory and Visual Warnings: At the time of the incident and minutes preceding the incident, 

were there any auditory or visual warnings of an approaching train? The categories below are 

related to this type of information. 

Train horn sounded before collision: The sounding of the train horn (along with other 

information, such as behavior or earphones) may provide information about whether the 

individual was aware of the approaching train or not. If the distance when the train horn sounded 

is indicated please enter the distance the train was from the individual.

1 = Yes, the report did mention that a train horn sounded 

2 =No, the report mentioned that no train horn sounded 

3 = The report did not mention a train horn sounding 

4 = Not applicable [such as in cases where a body is found on the tracks]

Also, specify train distance if known. 

Grade crossing safety enhancements: If the incident occurred at a grade crossing, were there 

any safety enhancements? If so, were they working? 

1 = Safety enhancements are present and working

2 = Safety enhancements are present but not working 

3 = Passive crossing

4 = Safety enhancements not mentioned but was at grade crossing 

5 = Not Applicable—Not at grade crossing

Distraction: Did the individual appear distracted during the minutes preceding collision with the 

train? Some examples are listed below and include wearing ear phones, looking at phone talking 

or texting, walking with another individual; accompanied by a dog or other animal? 

1 = Yes

2 = No
15 

3 = Not mentioned 

Earphones: Did the individual have earphones at the time of the incident? If yes, this may be an 

indication that the individual failed to hear the train prior to impact. If no earphone was listed in 

inventory then code as “no.” 

1 = Yes

2 = No

3 = Not mentioned 

Looking at phone or texting: Was the individual looking at their phone and texting prior to 

impact? If no phone was listed in inventory then code as “no.” 

1 = Yes

2 = No

3 = Not mentioned 

Talking on the phone: Was the individual talking on the phone prior to impact? If yes, this may 

indicate that they distracted by the conversation and were unaware of the oncoming train. If no 

phone was listed in inventory then code as “no.” 

1 = Yes

2 = No

3 = Not mentioned 

With other people: Was the individual with other people at the time of the incident? If so, does 

information in the report indicate that the other people were aware of the oncoming train (e.g., 

fled the tracks, tried to help the individual out of the way). 

1 = Yes

2 = No 

3 = Not mentioned 

With an animal (e.g., dog): Was the individual with an animal at the time of the incident? If so, 

briefly describe the circumstance (e.g., chasing a loose animal or standing next to service 

animal).

1 = Yes

2 = No

3 = Not mentioned 

Clothing: Was the individual wearing an item of clothing that may have obstructed their visual 

field of view at the time of the incident (e.g., hooded sweatshirt)?

1 = Yes

2 = No

3 = Not mentioned 
16 

Other distraction: If information (other than items included above) is provided that you feel 

shows the individual being distracted as the train approaches please enter a description here. If 

yes, specify the information. 

Individual seen at location prior to incident: If yes, please give description (such as what was 

said and by whom).

1 = Yes

2 = No

3 = Not mentioned 

Noted depression or withdrawal: If yes, please give description (such as what was said and by 

whom).

1 = Yes

2 = No

3 = Not mentioned 

Marked emotional reaction to recent event: If yes, please decide if it was a negative or 

positive event. If it is stated that the individual seemed happy and did not experience any recent 

life events then answer no. If there was no mention of having an event occurring in the 

individual’s life then respond with not mentioned. 

1 = Yes – Negative Event 

2 = Yes – Positive Event

3 = No

4 = Not mentioned 

III. Inconclusive Evidence: The information in this section describes the circumstances under 

which an inconclusive determination should be made.

Notable lack of evidence: Indicate yes only if there is a substantial lack of evidence to make any 

determination. If yes, please explain what type of information was missing.

1 = Yes (specify): _______________ 

2 = No

Evidence of alcohol or drugs at time of death: If yes, then intent cannot be determined based 

on state of mind. However if a direct factor of a probable suicide, suicide attempt, or probable 

accident is also included then the determination for intent can be completed. 

1 = Yes

2 = No

3 = Not mentioned 

TIDE Determination: 

1 = Probable suicide. The individual’s actions were intentional—they intended to harm 

themselves
17 

2 = Probable accident. The individual’s actions were unintentional—they did not intend to harm 

themselves

3 = Inconclusive. Insufficient information to determine probable intent of the individual 
18 

I. Direct Factors: 

Direct factors can be solely 

used to determine if suicide is 

the probable intent, or if the 

incident was a probable 

accident. 

II. Modifying Behaviors: 

Modifying behaviors add 

additional information to the 

factors described above 

including the direction that t he 

individual was facing, eye 

contact with t he engineer, and 

other behaviors that can be 

considered wit h other factors 

to infer probable su,c,de or 

Figure 2. TIDE Flowchart

accident. 

Ill. Inconclusive Factors: 

The infonmation available is 

not sufficient to determine a 

probable suicide or accident, 

or there is an indication of 

drug or alcohol use. 

r

Ar

**If there is an indication of drug or alcohol use atthe time of death, and there 

are no direct factors, skip directly to section Ill. Inconclusive Factors below. 

Are sufficient modifying behaviors described to infer probable suicide or 

accident? These include: 

• Direction individual was facing at the time of t he strike 

• Eye contact with the engineer 

• Individual seen at location prior to the incident 

• Distraction (e.g., earphone or cell phone use, presence of other people) 

• Audio and visual warnings (e.g., train horn or grade crossing safety 

enhancements) 

• Noted depression or withdrawal by others 

• Marked emot ional response to recent event by others who knew individual 

e there inconclusive factors described in the report, and therefore insufficient 

information to infer a probable suicide or accident? 

• Notable lack of detailed information in the report 

• Drugs or alcohol found at t he scene or behavioral indication of intoxication 

with no direct factors present 

Is there one or more direct factors described to infer a probable suicide or 

accident ? These include: 

• Presence of a suicide note 

• Statement of suicidal intent, an attempt, or accident 

• Behavior demonstrat es suicidal intent (e.g., jumping in front of the train at 

the last minute) or an accident (e.g., trying to beat the train, tripping) 

• Wording in report (e.g., wording includes suicide/ accident, intentional/ 

unintentional, or deliberate) 

,r .., Probable

Suicide 

Or 

Probable 

Accident 

, '" 

,r .., Probable 

Suicide 

Or 

Probable 

Accident '" ,, 

__ i_n_co_n_c_l_u_s _iv_.- e
19

Abbreviations and Acronyms

ACRONYMS EXPLANATION

CFR Code of Federal Regulations

ERA European Railway Agency

FRA Federal Railroad Administration

RD&T Research, Development and Technology

RSSB Railway Safety and Standards Board

TIDE Trespasser Intent Determination and Evaluation

UK United Kingdom

Volpe John A. Volpe National Transportation Systems Center