Temporary rumble strips consist of several raised bars arranged along a traffic lane to create tangible physical vibrations and noise to alert drivers to impending obstacles. These are usually made of plastic/polymer (e.g., recycled rubber), a strong and durable material that won’t be damaged or diminished as traffic runs over it. 

Transverse rumble strips run along the entire driving lane. These types of rumble strips are usually temporary, especially when used in a construction work zone.  The ease of installing and removing rumble strips have made them practical for use in work zones. The American Traffic Safety Services Association has developed a guide for use of temporary rumble strips in work-zones and classified them into 5 types. The main features of each type are as follows: Preformed thermoplastic strips are easy to install as these pre-cut products can be placed regardless of the temperature of the road. Pavement Marking tapes could be placed on top of each other until reaching the desirable thickness. Adhesive strips are produced with an adhesive backing which makes the installation and removal process easier while manually adhesive products can be found in different colors to improve visual detection. The last type, portable reusable strips, are ideal for short-term work-zones. Table 1 provides more information about different types of rumble strips that can be used near work-zones and their installation and removal procedures.

Table 1. Types of Temporary Rumble Strips and Their Installation Procedures

*Additional equipment may be required for cleaning or marking the roadway prior to rumble strip installation.
(source: https://www.workzonesafety.org/training-resources/fhwa_wz_grant/atssa_temporary_rumble_strips/)

To use rumble strips, one needs to make a professional judgment regarding their applicability, location, and installation process. The duration of work-zone activities, for instance, plays a significant role in selection the right type of products: thermoplastic rumble strips are only recommended if the process would take more than 3 days, while portable strips are suitable in short-term (within hours) road works. The configuration of strips is also pertinent to the performance of this solution. For instance, El-Rayes et al. (2013) pointed out that four configuration factors (i.e., spacing of rumble strips, type of rumble strips, type of vehicle, and vehicle speed) are correlated with the produced sound levels and consequently effectiveness of rumble strips.

Rumble Strips have a very small effect on productivity. They are easy to install and remove and can be reused, as well. 

Studies have shown that for greatest effectiveness, rumble strips need to be used together with other traffic control devices. This allows the rumble strips to do their main job of alerting drivers and bringing them to a high attention level so they can see a “caution sign” (e.g., slow speed ahead).

During this process, it is also important to think of the surroundings of the work zone to minimize disturbances to residents or businesses close to the work zone.

The following recommendations are provided by FHWA regarding the installation of rumble strips (Figure 2):

1.       Rumble strips should be between 7mm and 13mm thick and should be in a set of six spaced a maximum of 2.7 meters apart. At 50 mph or less, it is recommended to have gaps of 1.8 meters to 2.4 meters between rumble strips. At speeds greater than 50 mph, rumble strips can be spread strips 2.1-2.7 meters apart. Regular spacing between the singular strips could seem to drivers like regular control joints in the pavement (Figure 3). Irregularity in spacing is necessary to eliminate that misconception and properly alert the driver. Higher speeds require wider spacing between sets to provide enough time for drivers to reduce speed and become aware of the upcoming work zone area.

2.       Installation of temporary rumble strips should closely follow the department’s or manufacturer’s regulations/instructions, including details on air and pavement temperatures. If moisture is present in the air or on the pavement, cleaning of the pavement as well as choosing the proper adhesive are important.

3.       Temporary rumble strips should be used only when necessary. If audible and tactile warnings need to be provided for the safety of the workers or drivers, then rumble strips are highly recommended. Possible situations include detours, splitting lanes, lanes turning into exit/turn only, single lane traffic, stop light ahead, abrupt reduction in speed limit, and other varying traffic patterns.

Behzad Esmaeili, Ph.D. - University of Nebraska- Lincoln

Pouya Gholizadeh - University of Nebraska- Lincoln

Sogand Hasanzadeh - University of Nebraska- Lincoln

Erik Bruening - University of Nebraska- Lincoln

Brett Farquhar - University of Nebraska- Lincoln