67 Pa. Code § 212.302
(b) Warrants. In addition to the criteria in the MUTCD, the following applies:
(3) Warrant 9, ADT volume warrant.
(ii) This warrant is satisfied when the estimated ADT volumes on the major street and on the higher volume minor street or driveway approach to the intersection, when projected using an accepted procedure such as put forth in the Trip Generation Manual published by the Institute of Transportation Engineers, equals or exceeds the values in either Condition A or Condition B:
| Condition A—ADT Volume Warrant | |||||
| Number of Lanes for Moving Traffic on Each Approach | Estimated ADT* | ||||
| Major Street | Minor Street | Major Street (Both Approaches) | Higher-Volume Minor Street (One Direction Only) | ||
| 100% | 70%** | 100% | 70%** | ||
| 1 | 1 | 10,000 | 7,000 | 3,000 | 2,100 |
| 2 or more | 1 | 12,000 | 8,400 | 3,000 | 2,100 |
| 2 or more | 2 or more | 12,000 | 8,400 | 4,000 | 2,800 |
| 1 | 2 or more | 10,000 | 7,000 | 4,000 | 2,800 |
| Condition B—ADT Volume Warrant | |||||
| Number of Lanes for Moving Traffic on Each Approach | Estimated ADT* | ||||
| Major Street | Minor Street | Major Street (Both Approaches) | Higher-Volume Minor Street (One Direction Only) | ||
| 100% | 70%** | 100% | 70%** | ||
| 1 | 1 | 15,000 | 10,500 | 1,500 | 1,050 |
| 2 or more | 1 | 18,000 | 12,600 | 1,500 | 1,050 |
| 2 or more | 2 or more | 18,000 | 12,600 | 2,000 | 1,400 |
| 1 | 2 or more | 15,000 | 10,500 | 2,000 | 1,400 |
* Based on the volume projected to be present within 6 months of the opening of the development or within 2 years of the opening of the highway.
** May be used if the 85th percentile speed of the major street traffic exceeds 40 miles per hour or the intersection lies within the built-up area of an isolated community having a population of less than 10,000.