In order to improve our scientific understanding of how various species respond to the size and type of wildlife crossings, it is important to conduct wildlife monitoring both before and after construction. Monitoring should be accomplished using scientific methodology and results, and recommendations should be published so others benefit from what is learned.

On individual highway projects monitoring can help fine-tune mitigation measures like fencing, wildlife approaches to structures, and human use levels. Monitoring also helps determine the amount and type of wildlife use structures receive. Monitoring is important to maintain agency and public support and should be included in major highway projects that include wildlife crossings. However, there must also be a reasonable balance between the level of monitoring and the funds available for projects. DOTs will be concerned about the costs of building wildlife crossings, maintenance, and the cost of monitoring. The cost-effectiveness and support for future wildlife crossings depends on good science. Wildlife crossings can be extremely expensive, sometimes costing many millions of dollars for single highway projects.

Minimal monitoring may be necessary for species or issues that have been researched repeatedly. For example, there have been a number of studies done on wildlife crossings for black bear and deer. Many other wildlife species, like lynx and jaguar, have little or no research.

Monitoring can range from low-cost wildlife track counts and roadkill surveys to medium-cost motion-triggered camera traps and genetic analyses of scat and hair samples. In order to fully understand fine scale movement, higher cost GPS telemetry of wildlife may be needed.