A number of state legislatures have enacted laws granting immunity to officers when pursuing a fleeing suspect in vehicles when that suspect represents a threat to public safety. Further criteria with which to calculate the hazards versus benefits of continuing the pursuit include the time of day, weather conditions, traffic congestion, and presence of pedestrians. The guidelines generally do not give the officer enough wording or reasoning to justify continuing pursuit of a fleeing suspect whose speeds are becoming extreme. The officer must consider a number of factors, including the suspect's violence or threatened violence; the nature of the crime involved; the immediate threat posed by the suspect should apprehension be delayed; severity of the suspect's active resistance or attempts to evade; and whether citizens are involved in the pursuit. Once the decision is made to terminate the chase, the officer should be prepared to justify the decision to allow the suspect to escape.