4.1 Tracking Countermeasures
Implemented strategies should be monitored and evaluated to determine levels of success. These help provide accountability and can be used to keep stakeholders informed and engaged. A variety of methods can be employed to evaluate progress within an HSIP. Tracking countermeasures can be accomplished through the development of a table or spreadsheet, detailing implementation information and status. Columns A-D of Table 7provide examples of how installation information can be tracked.
Table 7. Example Table to Monitor Countermeasure Installation and Measure of Effectiveness Data.
| A. Strategy |
B. Status |
C. Agency |
D. Comment |
E. Effectiveness | |
|---|---|---|---|---|---|
| Pre-Install | Post Install | ||||
| West of the Main Street and Maple Street Intersection | |||||
| Advanced warning signs | Installed 8/15/11 | County DOT | Town collected ped/bike volumes in "post" period which increased by 20% compared to "pre" period | 1 crash in 3 yrs. | |
| Intersection of Main Street and Birch Avenue | |||||
| Advanced warning signs and marked crosswalks | Installed 8/17/11 | Town | Town collected ped/bike volumes in "post" period which increased by 20% compared to "pre" period | 1 crash in 3 yrs. 30% using x-ing | 50% using x-ing |
| Intersection of Main Street and Oak Terrace | |||||
| Median island with refuge | Planned with repaving schedule (3/3/12) | Town | Town collected ped/bike volumes in "post" period. | 2 crashes in 3 yrs. | |
| Intersection of Main Street and Chestnut Street | |||||
| Advanced warning signs | Installed 7/26/11 | Town | Town collected ped/bike volumes in "post" period which increased by 20% compared to "pre" period | 1 crash in 3 yrs. | |
| East of the Main and Chestnut Intersection | |||||
| Advanced warning signs | Installed 8/10/11 | County DOT | Town collected ped/bike volumes in "post" period which increased by 20% compared to "pre" period | 1 crash in 3 yrs. | |
4.2 Evaluating Effectiveness
Evaluating the effectiveness of non-motorized countermeasures after installation can provide valuable insights and direction regarding improving safety for non-motorized users in the future. The evaluation should focus on the quantifiable effects of the deployed countermeasures but could include qualitative feedback from safety stakeholders.
After countermeasures have been in place for at least one year, an interim evaluation can take place (see Table 7); however, at least three years of after data are required for a comprehensive evaluation of implemented strategies.
A before-and-after crash study can be conducted to evaluate the effectiveness of implemented strategies in improving safety when sufficient data are available. Details on creating a well-designed and executed before-and-after crash study can be found in A Guide to Developing Quality Crash Modification Factors(37) or in the Highway Safety Manual (HSM).(38)
In some cases, conducting a before-and-after study using crash data is not feasible due to the lack of non-motorized user crash data. When sufficient crash data are not available, other measures of effectiveness (MOEs) can be used to evaluate the safety performance of an implemented strategy. Some example MOEs include the following:
- Number of non-motorized users using a shoulder, path, sidewalk, or other linear facility or crossing.
- Percentage of non-motorized users travelling in the correct direction on the road (i.e., bicyclists and horse-and-buggies should travel with traffic and pedestrians against (or facing) traffic).
- Percentage of motor vehicles yielding at a non-motorized crossing.
- Motorized vehicle speed.
These MOEs are observed during a field study under similar periods and durations before and after implementation. As with crash-based evaluations of effectiveness, volume data for motorized and non-motorized users can help provide context on the results.