Vehicle Ramming Self-Assessment Tool
The tool's objective is to evaluate multiple user-defined areas of interest, prioritize them based on the evaluation criteria, and identify mitigation options for planning purposes. The two most common types of areas that users may evaluate are city streets--including sidewalks and pedestrian bridges where people gather or walk as part of daily activities--and special event areas.
The evaluation criteria in the tool are separated into three main categories:
- Environmental Characteristics, where the user can select properties for the entrances or openings within the area of interest that would allow vehicular access;
- Vehicle Size, which the tool suggests based on the environmental characteristics; and
- Pedestrian Factors, that evaluate the density of potential pedestrian population as well as other aspects such as congregation features and the ability of pedestrians to escape the potential area of attack.
Throughout the tool, helpful resources and references are noted. Users may further examine those resources online at cisa.gov/vehicle-ramming-attack-mitigation under the dropdown feature titled "Self-Assessment Tool Resources."
NOTE: Self-Assessment questions cannot be answered unless an area of interest is added and/or selected.
The measurements equate to the vehicle categories listed below:
- Less than 59" - Smaller than small passenger car - all-terrain vehicle (ATV) or golf cart
- 59" - 68" - Small passenger car
- 69" - 78" – Full-sized sedan
- 79" - 88" - Pick-up truck
- Greater than 88" - Standard test truck, Class 7 cab over, heavy-goods vehicle
Can the vehicle maneuver within the space?
- Yes – Objects exist that would prevent a vehicle from maneuvering in the space.
- No - Heavy objects and/or barriers exist that prevent a vehicle from maneuvering in the space.
Can a vehicle gain access to the environment from along the side of the street?
- No Vehicle/Smaller than Passenger Car - This selection draws a zero value and may be a golf cart or vehicle such as an ATV.
- Small Passenger Car (SC), Full Size Sedan (FS), Pick-up Truck (PU), Standard Test Truck (M), Class 7 Cab Over (C7), and Heavy Goods Vehicle (H) - The size of the vehicles is determined by the ASTM F2656/F2656M − 15 Standard
|Level of Service (LOS) - Population Density|
LOS A (>60 ft^2/ped)
At a walkway LOS A, pedestrians move in desired paths without altering their movements in response to other pedestrians. Walking speeds are freely selected, and conflicts between pedestrians are unlikely.
LOS B (>40-60 ft^2/ped)
At LOS B, there is sufficient area for pedestrians to select walking speeds freely to bypass other pedestrians, and to avoid crossing conflicts. At this level, pedestrians begin to be aware of other pedestrians, and to respond to their presence when choosing a walking path.
LOS C (24-40 ft^2/ped)
At LOS C, space is sufficient for normal walking speeds, and for bypassing other pedestrians in primarily unidirectional streams. Reverse-direction or crossing movements can cause minor conflicts, and speeds and flow rate are somewhat lower.
LOS D (15-24 ft^2/ped)
At LOS D, freedom to select individual walking speed and to bypass other pedestrians is restricted. Crossing or reverse flow movements face a high probability of conflict, requiring frequent changes in speed and position. The LOS provides reasonably fluid flow, but friction and interaction between pedestrians is likely.
LOS E (8-15 ft^2/ped)
At LOS E, virtually all pedestrians restrict their normal walking speed, frequently adjusting their gait. At the lower range, forward movement is possible only by shuffling. Space is not sufficient for passing slower pedestrians. Cross- or reverse-flow movements are possible only with extreme difficulties. Design volumes approach the limit of walkway capacity, with stoppages and interruptions to flow.
LOS F (>8 ft^2/ped)
At LOS F, all walking speeds are severely restricted, and forward progress is made only by shuffling. There is frequent unavoidable contact with other pedestrians. Cross-and reverse-flow movements are virtually impossible. Flow is sporadic and unstable. Space is more characteristic of queued pedestrians than of moving pedestrian streams.
Do any congregation features exist?
Are there sections of the environment where pedestrians can't escape?
Would pedestrians have a clear view?