Vehicle Ramming Self-Assessment Tool
In partnership with Chicago Police Department’s Crime Prevention and Information Center (CPIC), the Cybersecurity and Infrastructure Security Agency (CISA) developed the Vehicle Ramming Self-Assessment Tool to assist federal, state, and local law enforcement agencies, as well as critical infrastructure owners and operators inform planning considerations and protective measures associated with limiting risk against a vehicle-ramming method of attack.
The tool's objective is to evaluate multiple user-defined areas of interest, prioritize them based on the evaluation criteria, and identify risk reduction 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 (see note below); 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.
The results tab allows the user to see a prioritized list of the areas of interest that the user evaluates and their associated options for consideration. This feature allows the user to see which areas of interest merit the highest level of concern and to use the options for consideration for the planning process. The tool also provides references that allow users to find relevant resources for continuing research on barriers and other mitigation strategies. The topics addressed here reflect assessment methodologies and recommended practices that physical security professionals in public and private sector roles routinely use.
Note: Current ASTM standards for M-rated and S-rated barriers and the associated parameters for this tool were established before electric vehicles (EVs) became widespread on U.S. roads. As of 2023, EVs represent approximately 18% of new light-duty vehicle sales. These vehicles typically weigh between 6,000 lbs. and 9,000 lbs. More importantly, EVs possess significantly faster acceleration capabilities, allowing them to reach critical velocities over much shorter distances compared to traditional vehicles evaluated under current ASTM standards. Additionally, their quieter operation reduces auditory detection and situational awareness. Because of these factors, CISA recommends not only considering the next-higher size category for vehicles, as indicated by weight, but also incorporating protective measures and planning scenarios that account for the increased acceleration and quieter operational profiles of EVs. For detailed guidance tailored to specific environments, consult a professional protective design engineer.
Throughout the tool, helpful resources and references are noted. Users may further examine those resources online at cisa.gov/topics/physical-security/vehicle-ramming-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 - 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 2656/2656M-20 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?