Traffic Study Summary from MCDOT [edited]

This is a follow-up response to the request regarding crosswalk installation and traffic safety concerns at the intersection of Queen Elizabeth Drive and Shady View Lane. The Montgomery County Department of Transportation (MCDOT) appreciates the opportunity to assist you in this matter. We have completed our traffic engineering review at this location and would like to share our findings with you.

Queen Elizabeth Drive is classified as a primary residential roadway. In this capacity, it serves as a residential collector street acting as a conduit for vehicles from its adjacent side streets who wish to travel east and west. Based on the concerns we conducted 7 days’ speed studies, vehicles speed counts, on Queen Elizabeth Drive. These were conducted on when schools were in session to capture the most typical worst-case scenario traffic conditions. When assessing vehicle speeds we determine what is referred to as the 85th percentile speed. The 85th percentile speed is the speed at which 85 percent of the observed vehicles are traveling at or below. Our evaluation determined that the 85th percentile speed along Elizabeth Drive was 36 mph in the eastbound direction and 39 mph in the westbound direction. This means that 85 percent of the vehicles traveling along this portion of the roadway were doing so at or below these speeds. Please see the attached speed summary.

Although these speeds are in excess of the posted 30 mph speed limit, they fall below enforceable limits set when speed cameras are present. They also fall below the level that would trigger candidacy for speed humps set forth in our Speed Hump Regulation. When considering pedestrian crosswalks, it should be noted that they fall into two classifications: unmarked crosswalks and marked crosswalks. By law, an unmarked crosswalk exists at any intersection where there is a pedestrian point of origin and destination (such as a sidewalk). Marked crosswalks are typically installed after a study has determined that there is a moderate pedestrian presence throughout the day at that location and serves a two-fold purpose. First, they designate the locations where pedestrians can safely cross the road and secondly, a marked crosswalk serves to alert motorists that they should expect the presence of pedestrians in the roadway. When evaluating a location for the installation of a marked crosswalk, several factors are considered; this includes the presence of pedestrian generators (Metro station, shopping areas, convenience stores, etc.), vehicle volumes, and sight distance. In this case, the closest pedestrian generators would be the Ride On Bus stop and the Tanterra Pool.

Based on the request, we conducted a 13-hour count of vehicles, pedestrians, and bicyclists at this intersection. Please see the attached count summary. Our counts revealed that the combined pedestrian and bicyclists activity for the morning, midday and evening peak period (3 hours) was 10 crossing Queen Elizabeth Drive.

Based on our assessment at this location, pedestrian activity would be classified as light at best. The geometrics at this location provide adequate sight distance for motorists as well as for pedestrians wishing to cross Queen Elizabeth Drive. In addition, the observed traffic volumes and vehicle speeds are such that adequate gaps in traffic are available for those who may choose to cross the roadway at this location to safely do so. Please note that a marked crosswalk at a location with light pedestrian activity can be more dangerous as it may instill a false sense of security for the pedestrian and is also not respected by motorists who rarely, if ever, encounter a pedestrian. Based on our review, we believe that a marked crosswalk is not warranted along this portion of Queen Elizabeth Drive at this time.

In light of your safety concern, we conducted a review of police reported crash history for the most recent three-year period to determine if there were trends or problematic areas along Queen Elizabeth Drive near Shady View Lane intersection. Our review revealed that there were no reported crashes during this period. Based on our review, our recommendation would be to place our speed trailers or speed sentries along Queen Elizabeth Drive. These trailers display the posted speed limit along with the approaching vehicles speed to the motorists and are part of our Educational traffic calming strategy. This would be placed for a 5-day period, deploy on Monday and remove on Friday, schedule and weather permitting.

We will install pedestrian/bicyclist warning signs on both sides of Queen Elizabeth Drive approaching to the intersection. These signs will alert the motorists regarding presence of pedestrians/ bicyclist. In addition, we will install STOP bar along Shady View Lane. This will help motorists to see more while looking from Shady View Lane onto Queen Elizabeth Drive. These improvements will be implemented by late summer or early fall, schedule and weather permitting.

Thank you for your input and your partnership in our shared pursuit of traffic safety.

Traffic Engineering Studies Section

Division of Traffic Engineering & Operations

PDF Link - Study Attachment 1

PDF Link -Study Attachment 2