Abstract
These test methods define two categories of acceptance tests for evaluating the performance of highway traffic monitoring devices (TMD) according to the functions it performs, the data it provides, the required accuracy of the data, and the conditions under which the device operates. The tests are performed in a field environment and result in an accept or reject decision for the TMD under analysis. The first test is the Type-approval Test intended for TMDs that have never been type approved, and verifies the functionality of all features of the TMD by providing information for evaluating the accuracy of the data item outputs when monitoring vehicle flows consisting of a mix of all anticipated vehicle classes under a specified range of operating conditions. The second, the On-site Verification Test, is applicable to production versions of TMDs that have previously passed a Type-approval Test, but are now being installed at a new location or have been repaired. Lighting and weather factors that may be included as part of TMD testing are (1) dawn ambient lighting, (2) dusk ambient lighting, (3) nighttime ambient lighting, (4) sun glint, (5) rain characterized by rain rate, (6) fog or dust characterized by human visual range, and (7) snow characterized by snow fall rate and snow flake size.
Scope
1.1 Purpose—The two test methods contained in this standard define acceptance tests for evaluating the performance of a Traffic Monitoring Device (TMD) according to the functions it performs, the data it provides, the required accuracy of the data, and the conditions under which the device operates. Acceptance tests are recommended whenever a TMD is purchased, installed, or performance validation is desired. The tests are performed in a field environment and result in an accept or a reject decision for the TMD under test.
1.2 Exceptions—Exceptions and options to the test methods may be included in any derivative test method presented by a user as part of the procurement process for TMDs. Sellers may offer exceptions and options in responding to an invitation to bid.
1.3 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units, which are provided for information only and are not considered standard.
1.4 The following safety procedures apply to Sections 6 and 7, which describe the details of the acceptance test methods. When a test site accessible by the public (for example, a street or highway) is used for the acceptance test of the TMD, obtain approval from the public authority having jurisdiction over the site for the traffic control procedures to be used during the test. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
