When identifying sites to be used for local calibration, it is advisable to find sites that are similar to those used to develop the model. This approach will yield the most reliable local calibration factors. Why does lighting not have any CMF in freeway and ramp models?
Is the effect insignificant or has there not been data to support model development for this? It did indicate whether lighting was present at an intersection but there were not sufficient project resources to confirm the accuracy of this data element using a video log.
It appears from the examples that the CMF for weaving decreases with increasing traffic volumes. This seems counter intuitive. This trend was noted by the researchers and discussed in the Project Final Report 20 p. The following text is excerpted from the report. It indicates that the lane change CMF is larger for segments associated with lower volume ramps.
This trend may be explained by the fact that high-volume ramp flows tend to dominate the traffic stream such that a large portion of the traffic stream is changing lanes and all drivers are more aware of these maneuvers. This trend is logical and intuitive. As indicated near the end of the text, the analyst should be careful to change the freeway segment volume by the same amount as the change in ramp volume to ensure volume balance on the freeway and to get the correct results from the model.
Can the Predictive Method be applied to ramps providing two-way travel? The method can certainly be applied if the two directions of traffic are separated by a physical median barrier.
If there is no separation by a physical median barrier, the method can be applied with the understanding that it does not account for i. What is the difference between a connector ramp and entrance or exit ramp at service interchange? The connector ramps that are addressed by the ramp method include: outer connection, loop or semi-direct connection, and direct connection.
The key difference between connector and non-connector ramps is the speed at the terminal between the ramp and the crossroad. Non-connector ramps i. They have some type of traffic control for one or more ramp movements at the intersection of the ramp and the crossroad typically requiring a stop or yield.
Connector ramps do not have traffic control at the intersection of the ramp and the crossroad i. Connector ramps at service interchanges are assumed to have a "low speed" merge with the crossroad. Connector ramps at system interchanges are assumed to have a "high speed" merge with the crossroad. These low and high-speed distinctions are reflected in the ramp method where it recommends using the entrance ramp or exit ramp predictive model for connector ramps at service interchanges.
And, it recommends using the collector-distributor CD -road model for connector ramps at system interchanges. These distinctions are also reflected in the speed-prediction model that is part of the ramp method. For ramp terminals, the CMF for a channelization of a right turn lane is greater than 1.
Why is this the case? A channelized right-turn is defined as a right turn that has a triangular channelizing island on the left side of the driver at the intersection. As discussed in the Final Report for Project 20 , right-turn channelization does not provide an expected safety benefit.
This finding is rationalized that the channelization puts the right-turning driver in a suboptimal position for judging the adequacy of an entry gap on the crossroad. What is a CMF? A Crash Modification Factor CMF is a value that quantifies the expected change in crash frequency at a site as a result of implementing a specific countermeasure. A CMF can estimate the expected change in crash frequency for total crashes, a particular crash type, or a particular severity.
A CMF is expressed as:. A CMF can also be a crash modification function, which is a formula used to compute the CMF for a specific site based on its characteristics.
Crash modification functions are useful because it is not always reasonable to assume that a treatment will have the same safety effect at sites with different characteristics e. A crash modification function allows the CMF to change over the range of a variable or combination of variables. Who uses CMFs and how are they used?
CMFs are used by several groups of transportation professionals for various reasons. The primary user groups include highway safety engineers, traffic engineers, highway designers, transportation planners, transportation researchers, and managers and administrators. As tools in the safety evaluation process, CMFs can be used to:.
These base conditions represent the site conditions before implementation of a treatment. This allows comparison of treatment options against a specified reference condition. For example, CMF values for the effect of lane width changes are determined in comparison to a base condition of ft. Under the base conditions i. A countermeasure with a CMF equal to 1.
How do I apply a CMF? A CMF is a multiplicative factor applied to an estimate of the expected crash frequency. The estimate can represent a particular crash type or particular crash severity as specified in the HSM or in the underlying study associated with the treatment. There are examples at the end of this section that show sample calculations.
A smaller SE indicates more certainty in the results. The examples at the end of this document demonstrate application of the confidence interval. When selecting treatments and CMFs, it is important to make sure the treatment is applicable to the site of interest. For example, the same countermeasure used on different road types may have different effects. Therefore, applying a CMF at a location that does not correspond to the setting i. This could result in infrastructure investments that may not be as beneficial as expected.
When determining an appropriate CMF, consider the following factors for applicability in the context of specific projects: area type rural vs. Can a CMF have a different effect on different crash types? A CMF may have a different effect on different crash types or severities.
As an example, consider Table 2 which presents CMFs from Table of the HSM for installing a traffic signal at a rural stop-controlled intersection. Notice the CMF for all crash types and all severities is equal to 0.
In some cases, a treatment may increase certain crash types i. For example, notice that though the installation of a traffic signal is expected to reduce angle and turning crashes, it is actually expected to increase rear-end crashes, though the net benefit is an expected reduction in the overall crashes.
The potential for differential crash effects underscores the importance of properly applying CMFs—only apply CMFs to the applicable crash types and severities. How do I calculate the effect of multiple treatments at one site? If multiple countermeasures are implemented at one location, then common practice is to multiply the CMFs to estimate the combined effect of the countermeasures.
The likelihood of overestimation increases with the number of CMFs that are multiplied. Therefore, much caution and engineering judgment should be exercised when estimating the combined effect of more than three countermeasures at a given location. The CMFs being considered should all be applicable to the same conditions and location and be consistent with the conditions under which the CMF was developed.
It is important to consider that although implementing several countermeasures might be more effective than just one, it is unlikely the full effect of each countermeasure would be realized when they are implemented concurrently, particularly if the countermeasures are targeting the same crash type. For example, shoulder rumble strips and enhanced edgeline retroreflectivity would both target roadway departure crashes, so the CMFs for these treatments would be highly related.
In some cases, countermeasures may be implemented at the same location to target different crash types. For example, the installation of a pedestrian signal would be relatively independent of the installation of a left turn phase at an intersection, since the one addresses pedestrian-vehicle crashes while the other addresses left-turn opposite-direction crashes.
Likewise, the conversion of a left turn phase from permissive to protected along with the installation of an exclusive right turn lane would be fairly independent in that they target different crash types. Unless the countermeasures act completely independently for the same crash types, multiplying several CMFs is likely to overestimate the combined effect.
It is good practice to conduct an individual CMF sensitivity analysis for each countermeasure and retain the most influential CMF value for each specific target crash type so that the safety performance is not over estimated. Part D includes all CMFs which have been assessed through a literature review and inclusion process, including measures of their reliability and stability. These CMFs are applicable to a broad range of roadway segment and intersection facility types, not just those facility types addressed in the Part C predictive methods.
The CMFs in Part C are those which have been formally integrated into a particular safety-prediction methodology. Is that different than a Crash Modification Factor? How do you determine statistical significance using the standard error? A CMF is determined to be statistically significant if the specified confidence interval of the CMF does not include 1.
For a given CMF and standard error, the confidence interval will depend on the significance level that is used. The two most common significance levels are 0. The CMF for countermeasure A is 0. On the other hand, if the same CMF had a standard error of 0. CMFs can be applied in the roadway safety management process to help select countermeasures and prioritize projects through an economic evaluation e.
The roadway safety management process is a six-step process as shown in Figure 1 and outlined in the HSM. The Highway Safety Improvement Program HSIP Manual [3] identifies this process as planning, implementation, and evaluation, where planning covers problem identification, countermeasure identification, and project prioritization. In either case, CMFs can play a role in the countermeasure selection and project prioritization components of the roadway safety management process. While not directly applicable to the application of CMFs, one can develop new CMFs in the safety effectiveness evaluation component of the process.
Transportation professionals frequently use CMF values to identify countermeasures with the greatest safety benefit for a particular crash type or location.
The application of CMFs also helps to prioritize potential treatments and provides decision-makers with the information needed to identify cost-effective strategies. What are potential challenges to applying CMFs in the safety management process and opportunities to overcome these challenges? Potential challenges may arise when applying CMFs in the roadway safety management process. Many are directly related to limitations in the progress of CMF research, while others apply to the lack of understanding of CMFs.
Despite decades of advancement in CMF research, there are still knowledge gaps that present obstacles for practitioners seeking to apply CMFs in the roadway safety management process. The following are general challenges associated with the application of CMFs and opportunities to overcome challenges. The discussion includes specific concerns and lessons learned based on actual experiences with the application of CMFs in roadway safety management efforts.
A notable potential challenge is the availability of CMFs for specific countermeasures. However, CMFs are still lacking for a large number of treatments, especially combination treatments and those that are innovative and experimental in nature.
Furthermore, CMFs may not be available for certain crash types and severities. CMFs are developed based on a sample of sites with specific conditions. While a CMF may be available for a given treatment, it may not be appropriate for the scenario under consideration.
For example, there may be significant differences between the characteristics of a proposed treatment site and the sites used to develop the CMF e. A related challenge may be that multiple CMFs exist for the same treatment and conditions. This is particularly challenging when multiple studies have estimated CMFs for the same countermeasure and combination of crash type and severity level, but yielded dissimilar results. If the CMFs also apply to the same roadway characteristics, then the selection can become even more difficult.
A star quality rating—which appraises the overall perceived reliability of a CMF using a range of one to five stars—is provided by the CMF Clearinghouse and may be helpful in these circumstances to identify the most suitable CMF. However, the ratings of the different CMFs may be similar as well. If the various CMFs have a fairly small range of values, then this situation may not be of great concern.
Yet, it is possible for the CMFs to vary significantly and even have contradictory expected outcomes i. In such cases, this potential situation would be highly challenging to overcome. A specific challenge could be that there is insufficient expertise within an agency to apply CMFs. While CMFs are not a new tool, they have only recently gained popularity among safety professionals.
There are a number of opportunities to apply CMFs in aspects of transportation engineering e. Where multiple people or agencies applying CMFs within a State, there is the potential for inconsistency with respect to the selection and application of CMFs.
Some State transportation agencies have addressed this by selecting or designating the CMFs appropriate for use within their State or jurisdiction.
To quantify the expected safety performance for a given alternative, it is necessary to estimate the annual crashes without treatment. The applicable CMFs are then applied to the annual crashes without treatment to estimate the annual crashes with treatment. The annual crashes without treatment can be estimated using several methods, with each bringing certain strengths and weaknesses. The most basic approach is to use the observed crash history of the site of interest i. This method is relatively simple but is highly susceptible to regression-to-the-mean bias i.
Another option to estimate annual crashes without treatment is to employ SPFs, which provide the predicted number of crashes. SPFs help to account for the random nature of crashes at a single site by incorporating data from other similar sites.
The drawback to using SPFs is that, unless they are developed using local data, they may not accurately reflect local conditions and again could overestimate or underestimate the annual crashes without treatment. The HSM presents the Empirical Bayes method as yet another option, which combines both the observed crash history of a site and the predicted crashes from the SPF to compute the expected crashes.
The prior discussion assumes that the crash history is available and applicable for a given site. In some cases, the crash history may not be available e. For both scenarios, it may be necessary to rely on SPF predictions, but it is suggested that the SPFs be calibrated to local conditions before applying them, whenever possible. What HSM-related tools are available? What is Safety Analyst?
It incorporates state-of-the-art safety management approaches into computerized analytical tools for guiding the decision-making process to identify safety improvement needs and develop a system-wide program of site-specific improvement projects. How can my agency obtain the Safety Analyst software?
The HSM Part C predictive methods were developed for application in the project development process, to quantify the safety performance of an existing facility and of proposed alternative improvements to the existing facility. For this reason, HSM Part C has extensive input data requirements; it is presumed that all of the HSM Part C input data should be available during the development or design of a particular project.
AASHTOWare Safety Analyst includes procedures to quantify the safety performance of an existing facility and of proposed alternative improvements to the existing facility, but these procedures are simpler and less sophisticated than the procedures used in HSM Part C.
As a result, the required input data set for AASHTOWare Safety Analyst is much less extensive than for HSM Part C, including only those items that are essential for analyses and which would be reasonable to expect could be assembled for the entire highway network.
Thus, AASHTOWare Safety Analyst is generally best suited to planning-level analysis of potential alternative improvements and HSM Part C is best suited to detailed analysis of potential alternative improvements as part of the project development process and design.
Intended users include highway project managers, designers, and traffic and safety reviewers in State and local highway agencies and in engineering consulting firms. The CPM estimates the frequency of crashes expected on a roadway based on its geometric design and traffic characteristics. The crash prediction algorithms consider the effect of a number of roadway segment and intersection variables.
Can default crash severity and crash type distribution values be updated with agency-specific values in IHSDM? Where can I find the latest version of the HSM spreadsheet tools? Please check back periodically to ensure that you are using the most up-to-date version for all predictive crash analyses. Users manually enter data for each individual segment, interchange, and cross street.
What is the CMF Clearinghouse? The Crash Modification Factors Clearinghouse houses a web-based database of CMFs along with supporting documentation to help transportation engineers identify the most appropriate countermeasure for their safety needs. Using this site at www. What is the purpose of the CMF Clearinghouse?
New CMFs will be identified via a periodic review of published literature. In addition, the CMF Clearinghouse provides a mechanism for transportation professionals to submit documentation of new CMFs to be considered for inclusion. Educational information on CMFs includes the "About CMFs" page, which summarizes useful information in the form of answers to frequently asked questions.
The "Resources" page provides additional information on related trainings and publications. Where available, a link is provided to the publication from which the CMF was extracted.
The CMF Clearinghouse reports this information in a standard format to enable users to make educated decisions about the most applicable CMF to their condition. The star quality rating is assigned based upon the standard error of the CMF value, as well as the design, potential biases, data source, and sample size of the study that developed the CMF.
The CMFs that are included in the Highway Safety Manual will typically have a higher star quality rating given the strict inclusion criteria. The burden is on the user to determine the most appropriate CMF for their analysis need.
This determination should be made based upon the CMFs applicability to their condition i. The Crash Modification Factors Clearinghouse is just one of the tools and resources available to help transportation professionals make safety decisions. The first edition of the Highway Safety Manual, released in , provides practitioners with the best factual information and tools to facilitate roadway design and operational decisions based on explicit consideration on their safety consequences.
The HSM also covers many other important topics for highway safety, including safety fundamentals, road safety management, and predictive methods. A significant difference between these two resources is in how the CMF values are presented. For each treatment in the HSM, one CMF is presented for a given crash type or severity based on the best available research. The CMF may be based on a single study or may represent an aggregate value based on multiple studies.
This book — available as a free download in PDF or iBook format — addresses the usability and cognitive support issues related to EHRs. Quality improvement is an important, established practice in healthcare, and you can find opportunities to merge electronic health records EHRs with quality improvement throughout all phases of care.
Here are three examples:. Below, we explain these capabilities and discuss how you can use your EHR to reach your quality improvement goals. CDS could be as basic as using a reference text to double-check a treatment algorithm. They can present both general and person-specific information, filtered and organized, at appropriate times to appropriate people, including clinicians, practice staff, and patients.
Clinical decision support CDS helps physicians talk with patients about which imaging tests are appropriate for their situation. These tools can help avoid unnecessary medical tests, resulting in higher-quality patient care at a lower cost.
Clinical quality measures CQMs gauge and track the quality of healthcare services to help find areas that need improvement, and payers are increasingly examining them.
Properly implemented EHR systems can calculate quality measures, and results can help clinicians with practice improvement. Results can also be transmitted to payers, thus streamlining quality reporting. Properly implemented EHR systems can also help clinicians — especially those who participate in a clinical data registry — to measure and improve their care quality performance. EHRs extract and transmit data that is collected during normal care and documentation.
Compared with manual methods, this makes it easier to abstract data, calculate measurements, and provide feedback. Electronic clinical quality improvement eCQI uses a variety of processes, including health IT tools, to help improve care and to support better health. It uses technology effectively to sustain a continuous improvement cycle, and at its core is the traditional quality improvement process model. The next stage of healthcare quality includes advanced CDS and increased end-to-end electronic quality measurement and reporting.
Use the following tools and links to further your understanding of electronic clinical quality improvement. Composed of official partners and 20 federal agencies, its continuing mission is to optimize care, keep people healthy, and improve outcomes for priority populations.
Learn more about how you can use electronic health records EHRs to improve the quality of patient care. These resources will help you:. Overview Access to extensive eCQI resources and connections to professionals dedicated to clinical quality improvement for better health, including introductory material describing the basic technical aspects of eCQM reporting in addition to in-depth technical details.
This page features select resources and highlights newly released resources for individuals interested in developing and engaging in leadership opportunities at the local, state, and national levels; and it is meant to assist the work of individuals engaged in formal leadership positions at the state association level.
Podcasts Download podcasts to stay informed about current topics in schoool psychology in a convenient, on-the-go format. Search by Topic Search. Mental Health School Psychology and Mental Health School psychologists are uniquely positioned in schools to facilitate the development, delivery, and monitoring of prompt, effective, and culturally responsive mental and behavioral health services of prevention and intervention. Special Education Intelligent Lives Film Partnership NASP is partnering with award-winning director Dan Habib on his Intelligent Lives film, a catalyst to transform the label of intellectual disability from a life sentence of isolation into a life of possibility.
Diversity Social Justice NASP has developed and identified resources to help schools and families engage in constructive dialogue and action regarding social justice that affect children's learning and well-being, including issues of poverty, race, privilege, violence, and economic isolation.
In the decades that followed, the practice was widely adopted despite no significant research showing that these contracts were effective. In a paper , M. Linehan , who developed Dialectical Behavioral Therapy and, with it, these commitment to treatment statements. In the Baylor University journal article referenced above, the authors propose that a formulaic crisis plan could look like this:.
Step 1. Step 2. Write out and review more reasonable responses to my suicidal thoughts, including thoughts about myself, others, and the future.
Step 3. Step 4. Try and do the things that help me feel better for at least 30 minutes listening to music, going to work out, calling my best friend. Step 5. Repeat all of the above at least one more time. Step 6. Step 7. Image Description: Blue background with a white, spiral-bound notebook in the center. Through Patreon, you can get instant access to download all printable PDFs, licensing for professional use, and early releases- all while supporting the creation of more resources.
This post contains linked products from which I may earn a commission. As an amazon associate, I earn from qualifying purchases. Click here to jump to a detailed image description. The educational resources included on this site are not therapy and do not replace mental health treatment or crisis services. For more information see Terms of Use. Contents hide. Crisis Planning Conversations. Creating this Safety Plan Printable.
Download This Printable Safety Plan. Who should make a crisis plan?
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