Traffic and Safety

(@joe.gustafson)

Traffic and Safety

Effectiveness of Traffic Control Devices to Reduce Unsafe Crosswalk Encroachment

Right turn movements made on a steady red circular traffic signal are allowed in Minnesota except when specifically prohibited by signage. Allowing right turns on red (RTOR) significantly improves intersection efficiency and reduces traffic conflicts by preventing unnecessary cycling of the traffic signal to serve right turns. However, drivers making RTOR often encroach into pedestrian crosswalks in order to look left... more »

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(@joe.gustafson)

Traffic and Safety

Are modern headlight designs hazardous to pedestrian safety?

Vehicular headlight design continues to evolve with greater control over light dispersion patterns. Increasingly, newer vehicles feature forward lighting that projects strong illumination on the roadway surface but very weak illumination above a certain level (the cutoff). This sharpened distribution of light entails several known challenges including reduced light output towards traffic signs (roadside and overhead),... more »

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(@joe.gustafson)

Traffic and Safety

Design of Channelized Right Turns to Maximize Safety and Accessibility for Nonmotorized Users

Channelized right turns can provide significant benefits for intersection operation by allowing right turns to bypass the main intersection. Channelized right turns also have the potential to provide safety benefits for pedestrians and shared-use path cyclists by reducing multiple-threat risk and improving sight lines for both motorized and nonmotorized users on the approach to their point of potential conflict. In... more »

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(@kenjohnson)

Traffic and Safety

Pavement Marking/Colored Pavement Friction Differential and Product Durability

Pavement markings, by their nature, tend to be slippery since glass media is added to provide retroreflectivity. Pedestrians (including those with disabilities), motorcyclists, and bicyclists are impacted by slippery pavement markings. There are available pavement marking and colored pavement products that provide additional friction and that show promise from a durability standpoint. These products have been used... more »

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(@maria)

Traffic and Safety

Roundabouts: Are design practices ADA compliant?

The Minnesota Council on Disability (MCD) has raised concerns about the safety of methods currently employed for crossing at Minnesota Roundabouts for pedestrians with disabilities. Representatives of the Council recently approached MnDOT to bring awareness and discuss some concerns about current design practices. Because roundabouts offer so many beneficial features to a Minnesota community, it is important that they... more »

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2 votes
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(@maria)

Traffic and Safety

Pedestrian Features on Roundabouts

The accommodation of safe pedestrian movement at roundabouts needs to be studied with respect to a broad range of surrounding pedestrian facility types, contexts, and pedestrian crossing control features. Examples of pedestrian crossing control to be studied include: warning devices such as Rapid Rectangular Flashing Beacon(RRFB), crosswalk configurations and locations with respect to roundabout geometry, and other pedestrian... more »

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1 vote
1 up votes
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(@shuo.wang)

Traffic and Safety

Evaluating the Impacts of Construction Projects on Transit Service Performance

Corridors such as I-35W and I-494 in the Twin Cities region have been undergoing major construction projects. During project scoping, preliminary plan development stage and construction stage, the Transportation Management Plan (TMP) offers mitigation strategies to minimize work zone impact. Research is needed on how transit operations is impacted by these construction projects and develop possible transit mitigation... more »

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3 votes
3 up votes
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(@nlmorris)

Traffic and Safety

Driver Comprehension of Flashing Yellow Arrows

Flashing yellow arrows are frequently deployed to smooth left-turning traffic at signalized intersections. While FHWA considers the flashing yellow arrow as a dramatic safety improvement on the green ball and that it is intuitive to drivers, driver complaints about their confusing state and some high profile crashes call into question their mainstream comprehension. An added complication is the various light arrangments... more »

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5 votes
5 up votes
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(@nlmorris)

Traffic and Safety

Transverse Rumble Strips at Rural Intersections

Transverse rumble strips have been deployed at rural intersections to help reduce serious and fatal crashes. However, FHWA lists them as "tried" rather than "proven" due to conflicting research findings. Further research is needed to determine the role that transverse rumble strips have in alerting distracted/unaware/or fatigued drivers of upcoming intersections and if the lack of efficacy is more related to improper... more »

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3 votes
3 up votes
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(@nlmorris)

Traffic and Safety

Will lowering roadway speeds change driver speeds?

Legislation has been proposed to allow Class 1 cities to reduce their minimum posted roadway speeds. It should be better examined the extent to which roadway speed changes without any additional infrastructure changes (e.g., road diet, center median, lane narrowing) will have on changing driver speeds. This research could help inform policy and practices statewide on speed limit changes to best achieve the safety goals... more »

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9 votes
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(@robert.chaucierre)

Traffic and Safety

TH 55 Connected Corridor Project Evaluation

Need a case study report to document the installation and development of the TH 55 Connected Corridor Project, evaluate the function of the Dedicated Short Range Communication (DSRC) radios, assess the ongoing system diagnosis and maintenance needs, and identify opportunities. This Connected Corridor project is a response to the American Association of State Highway and Transportation Officials (AASHTO) Signal Phase... more »

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4 votes
4 up votes
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(@jay.hietpas)

Traffic and Safety

Assessing Pavement Markings for Automated Vehicle Readiness

Are Minnesota's pavement marking standards ready for automated vehicles? The answer is, we don't know. The risk is, this technology is developing at a rapid pace, which can impact the safety and operation of state, county, city and township roads. Vehicles are being produced today that use pavement markings for lane keeping assist and lane keeping control functions. Manufacturers are starting to include these as... more »

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5 votes
5 up votes
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(@andrew.andrusko)

Traffic and Safety

Develop National Standards for Truck Parking Information Management Systems

Minnesota recently implemented a live, real time truck parking information system along with other MAASTO/Mid-America Freight Coalition states in the Midwestern region. This system incorporated several standards to ensure that trucking companies, mapping companies and other consumers of the data would be able to access the live data. As other states have developed or are in the process of developing their own TPIMS type... more »

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(@nlmorris)

Traffic and Safety

Using the ITE Signal Timing Formula for Expected Driver-Pedestrian Yielding Distances

The ITE signal-timing formula [1] governs the time duration of traffic control signal indications, given the speed of road vehicles and road grade, along with other factors. The same formula has been used for the investigation and enforcement of pedestrian stopping laws, given the distance of the vehicle when the pedestrian steps onto a crosswalk [2]. However, in the ITE formula, the time given to drivers to perceive,... more »

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7 votes
7 up votes
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(@duane.hill)

Traffic and Safety

Rumble Strip vs Mumble Strip

The sound made by standard rumble strips has a quality of life impact on the environment near locations where they are installed. These can be heard from over a mile away. The sound is alarming to residents and citizens that are near the roadway. Sinusoidal "mumble" or "quiet" rumble strips have been developed to mitigate the sound created by standard rumble strips. An alternative analysis needs to be performed to... more »

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22 votes
23 up votes
1 down votes