Guidelines for Removal of Traffic Control Devices in Rural Areas, TR-527, 2005

It is commonly regarded that the overuse of traffic control devices desensitizes drivers and leads to disrespect, especially for low-volume secondary roads with limited enforcement. The maintenance of traffic signs is also a tort liability concern, exacerbated by unnecessary signs. The Federal Highway Administration’s (FHWA) Manual on Uniform Traffic Control Devices (MUTCD) and the Institute of Transportation Engineer’s (ITE) Traffic Control Devices Handbook provide guidance for the implementation of STOP signs based on expected compliance with right-of-way rules, provision of through traffic flow, context (proximity to other controlled intersections), speed, sight distance, and crash history. The approach(es) to stop is left to engineering judgment and is usually dependent on traffic volume or functional class/continuity of system. Although presently being considered by the National Committee on Traffic Control Devices, traffic volume itself is not given as a criterion for implementation in the MUTCD. STOP signs have been installed at many locations for various reasons which no longer (or perhaps never) met engineering needs. If in fact the presence of STOP signs does not increase safety, removal should be considered. To date, however, no guidance exists for the removal of STOP signs at two-way stop-controlled intersections. The scope of this research is ultra-low-volume (< 150 daily entering vehicles) unpaved intersections in rural agricultural areas of Iowa, where each of the 99 counties may have as many as 300 or more STOP sign pairs. Overall safety performance is examined as a function of a county excessive use factor, developed specifically for this study and based on various volume ranges and terrain as a proxy for sight distance. Four conclusions are supported: (1) there is no statistical difference in the safety performance of ultra-low-volume stop-controlled and uncontrolled intersections for all drivers or for younger and older drivers (although interestingly, older drivers are underrepresented at both types of intersections); (2) compliance with stop control (as indicated by crash performance) does not appear to be affected by the use or excessive use of STOP signs, even when adjusted for volume and a sight distance proxy; (3) crash performance does not appear to be improved by the liberal use of stop control; (4) safety performance of uncontrolled intersections appears to decline relative to stop-controlled intersections above about 150 daily entering vehicles. Subject to adequate sight distance, traffic professionals may wish to consider removal of control below this threshold. The report concludes with a section on methods and legal considerations for safe removal of stop control.

Mississippi Drive (Iowa 92) from Main Street to the Norbert F. Beckey Bridge in Muscatine, Iowa, STP-U-5330(614)—27-70, Muscatine County, 2015

The proposed action consists of upgrading Mississippi Drive (Iowa Highway 92) through downtown Muscatine, Iowa. The Mississippi Drive Corridor Project begins south of the Main Street/Grandview Avenue intersection, continuing to the East 2nd Street/Norbert F. Beckey Bridge intersection, which marks the end of the project. It passes through a mix of commercial, residential, Central Business District and industrial land uses. The total length of the project is approximately 1.6 miles, including 19 intersections (6 with traffic signals). Refer to the vicinity map on Figure 1. The current roadway is a 3- to 4-lane, urban facility with both divided and undivided medians. The roadway, ranging from 40 to 64 feet wide, is considered difficult to cross for pedestrians, especially for small children or elderly. The width of this roadway is being considered to be narrowed to improve the accessibility to the downtown from the Mississippi River riverfront area by pedestrians. This project also includes accommodations for bicycles and pedestrians and measures to reduce flooding on the roadway.

East 1 St Street Interchange and I-35 Widening, From MP 94.3 to Oralabor Road, Polk County, Iowa, Project # IM-035-4(140)92--13-77, Environmental Assessment and Section 4(f) De Minimis Impact Finding, 2015

From Proposed Action: "The proposed action consists of reconstructing the East 1st Street/I-35 interchange with a Diverging Diamond interchange, widening I-35 from four (4) lanes to six (6) lanes, and widening East 1st Street from four (4) lanes to five (5) lanes from Delaware Avenue to Frisk Drive. The project also proposes to reconstruct the intersections of East 1st Street/Creekview Drive and East 1st Street/Frisk Drive."

Remote Sensing (LIDAR) for Management of Highway Assets for Safety, 2003

The main objective of this study was to utilize light detection and ranging (LIDAR) technology to obtain highway safety-related information. The safety needs of older drivers in terms of prolonged reaction times were taken into consideration. The tasks undertaken in this study were (1) identification of crashes that older drivers are more likely to be involved in, (2) identification of highway geometric features that are important in such crashes, (3) utilization of LIDAR data for obtaining information on the identified highway geometric features, and (4) assessment of the feasibility of using LIDAR data for such applications. A review of previous research indicated that older drivers have difficulty negotiating intersections, and it was recognized that intersection sight triangles were critical to safe intersection negotiation. LIDAR data were utilized to obtain information on potential sight distance obstructions at six selected intersections located on the Iowa Highway 1 corridor by conducting in-office line-of-sight analysis. Crash frequency, older driver involvement, and data availability were considerations in the selection of the six intersections. Results of the in-office analysis were then validated by visiting the intersections in the field. Sixty-six potential sight distance obstructions were identified by the line-of-sight analysis, out of which 62 (89.8%) were confirmed while four (5.8%) were not confirmed by the video. At least three (4.4%) potential sight distance obstructions were discovered in the video that were not detected by the line-of-sight analysis. The intersection with the highest crash frequency involving older drivers was correctly found to have obstructions located within the intersection sight triangles. Based on research results, it is concluded that LIDAR data can be utilized for identifying potential sight distance obstructions at intersections. The safety of older drivers can be enhanced by locating and rectifying intersections with obstructions in sight triangles.

Rural Expressway Intersection Synthesis of Practice and Crash Analysis, 2004

This report presents a national synthesis of rural expressway, two-way stop -controlled (TWSC) intersection safety strategies and intersection designs and an analysis of Iowa expressway TWSC intersection crash characteristics. A rural expressway is a multi-lane highway with a divided median and with mostly at -grade intersections, although some intersections may be grade separated. The synthesis of intersection strategies is conducted in two parts. The first is a literature review and the second part is a national survey of strategies currently being applied by state transportation agencies. The characterization of crash patterns at TWSC expressway intersections is examined through the analysis of 5 years of crash data at 644 intersections.

The Effectiveness of Iowa's Automated Red Light Running Enforcement Programs, 2007

The Federal Highway Administration estimates that red light running causes more than 100,000 crashes and 1,000 fatalities annually and results in an estimated economic loss of over $14 billion per year in the United States. In Iowa alone, a statewide analysis of red light running crashes, using crash data from 2001 to 2006, indicates that an average of 1,682 red light running crashes occur at signalized intersections every year. As a result, red light running poses a significant safety issue for communities. Communities rarely have the resources to place additional law enforcement in the field to combat the problem and they are increasingly using automated red light running camera-enforcement systems at signalized intersections. In Iowa, three communities currently use camera enforcement since 2004. These communities include Davenport, Council Bluffs, and Clive. As communities across the United States attempt to address red light running, a number of communities have implemented red light running camera enforcement programs. This report examines the red light running programs in Iowa and summarizes results of analyses to evaluate the effectiveness of such cameras.

In-Pavement Pedestrian Flasher Evaluation: Cedar Rapids, Iowa, 2004

Numerous strategies have been experimented with nationwide in an attempt to reduce the overall number of pedestrian-vehicle crashes, especially in instances where improper crossing or failure to yield was the proximate cause of the crash. Some of these measures include overhead signs, flashing warning beacons, advanced crossing signs, more visible pavement markings, in-street “Yield to Pedestrian” signs, and more recently, in-pavement flashing lights. Pedestrian safety has been a key issue for the City of Cedar Rapids, Iowa, in particular at non-controlled intersections and mid-block crossings. In 2002, the city council gave preliminary approval to implement a pedestrian-actuated overhead flasher system in conjunction with an in-pavement flasher system at the intersection of 1st Avenue NE and 4th Street NE in the downtown central business district. This location is uncontrolled and has several elements that can create conflicts between pedestrians, vehicles, and trains that service local industry. This report summarizes the results from a small-scale study completed by CTRE to evaluate the effectiveness of the in-pavement flasher system installed in downtown Cedar Rapids. The installation of in-pavement flashing warning lights at the pedestrian crosswalk at this site has had a net positive effect on the safety characteristics of the location. The results of this study show a marked improvement in motorist compliance with the state law requiring that motorists yield to pedestrians in the crosswalk. The pedestrian and motorist surveys show that both groups felt the in-pavement flashing lights have increased motorist awareness, especially at night. The data indicate the in-pavement flashing warning lights improved the motorists' response to pedestrians in the area, and that the system could be operational throughout summer and winter conditions.

In-Street Yield to Pedestrian Sign Application in Cedar Rapids, Iowa, 2003

Vehicle-pedestrian crashes are a major concern for highway safety analysts. Research reported by Hunter in 1996 indicated that one-third of the 5,000 vehicle-pedestrian crashes investigated occurred at intersections, and 40 percent of those were at non-controlled intersections (Hunter et al. 1996). Numerous strategies have been implemented in an effort to reduce these accidents, including overhead signs, flashing warning beacons, wider and brighter markings on the street, and advanced crossing signs. More recently, pedestrian-activated, in-street flashing lights at the crosswalk and pedestrian crossing signs in the traffic lane have been investigated. Not all of these strategies are recognized as accepted practices and included in the Manual on Uniform Traffic Control Devices (MUTCD), but the Federal Highway Administration (FHWA) is supportive of experimental applications that may lead to effective technology that helps reduce crashes.

Traffic Signal Inventory Project, 2001

The Center for Transportation Research and Education performed a traffic signal inventory study for the Iowa Department of Transportation. The purpose of this study was to determine the level of compliance with the Manual on Uniform Traffic Control Devices (MUTCD) and other industry standards of traffic signals on the state highway system. Signals were randomly selected throughout the State of Iowa. Only signals in cities with a population less than 5,000 were considered. Several intersections need to be addressed immediately to correct clearance timing settings. Red clearance intervals were frequently too short. A handful of intersections had inadequate pedestrian clearance times. Six intersections had at least one yellow clearance interval that did not meet Institute of Transportation Engineers standards. Some of the intersections likely would not meet traffic signal warrants and should be investigated for possible removal. The most common problem found with traffic signals was a lack of maintenance. Many of the signals had at least one of the following problems: burned out lights (signals and/or pedestrian heads), pedestrian lenses in need of replacement, dirty cabinet/missing or poor filter, missing visors, or inoperative pedestrian push buttons. Timing sheets were frequently missing or out of date. Another frequent noncompliance issue was the use of backplates. The MUTCD states that backplates should be used on signals viewed against a bright sky. The majority of signals inventoried did not have backplates on the mast-arm mounted signals. The timing at some intersections could likely be improved by reducing the cycle length. Where there were multiple signals in close proximity rarely was there any attempt at signal coordination. Finally, a number of intersections had equipment that by today’s standards would be considered obsolete.

High Priority Corridors for Access Management Near Large Urban Areas in Iowa, 2002

This research project was intended to produce a strategy for addressing current and future access management problems on state highway routes located just outside urban areas that serve as major routes for commuting into and out of major employment centers in Iowa. There were two basic goals: (1) to develop a ranking system for identifying high-priority segments for access management treatments on primary highways outside metro and urban areas and (2) to focus efforts on routes that are major commuting routes at present and in the future. The project focused on four-lane expressways and two-lane arterials most likely to serve extensive commuter traffic. Available spatial and statistical data were used to identify existing and possible future problem corridors with respect to access management. The research team developed a scheme for ranking commuter routes based on their need for attention to access management. This project was able to produce rankings for corridors based on a variety of factors, including proportion of crashes that appear to be access-related, severity of those crashes, and potential for improvement along corridors. Frequency and loss were found to be highly rank correlated; because of this, these indicators were not used together in developing final priority rankings. Most of the highest ranked routes are on two-lane rural cross sections, but a few are four-lane expressways with at-grade private driveways and public road intersections. The most important conclusion of the ranking system is that many of the poor-performing corridors are located in a single Iowa Department of Transportation district near two urban areas--Des Moines and Ames. A comprehensive approach to managing access along commuting corridors should be developed first in this district since the potential benefits would be highest in that region.

Corridor Management Pilot Projects, 2004

Managing existing and newly constructed highway corridors has recently become a significant concern in many states, including Iowa. As urban land and land on the urban fringe develops, there is pressure to add features such as commercial driveways, at-grade public road intersections, and traffic signals to arterial highway routes that should primarily serve high-speed traffic. This diminishes the speed and traffic capacity of such roadways and can also cause significant safety issues. if mobility and safety are diminished, the value of the highway investment is diminished. Since a major highway corridor improvement may cost tens of millions of dollars or more, corridor management is as critical to preserving that investment as is more "hard side" management practices such as pavement or bridge management. Corridor management is a process that applies access management principles to highway corridors in an attempt to balance the competing needs of traffic service, safety, and support for land development. This project helped to identify routes that should be given high priority for corridor management. The pilot study in the form of two corridor management case studies provides an analytical process that can be replicated along the other Iowa commuting corridors using commonly available transportation and land use data resources. It also offers a general set of guidelines for the Iowa Department of Transportation to use in the development of its own comprehensive corridor management program.

Access Management: A Review of Recent Literature, 1996

The Iowa Department of Transportation's Access Management Task Force was established as part of the Iowa Department of Transportation's overall Safety Management System (SMS) effort. The goal of the Access Management Task Force is to develop a program designed to educate and market the concept and benefits of access management to landowners and developers, professional planners and engineers, planning and zoning staff members, appointed and elected officials, and motorists. Access management is pursued through the design and control of driveways, curb cuts, turning movements, interior circulation of parking lots, and public street connections and intersections. Usually, state highways or major urban and suburban arterial streets are the targets of access management projects. Access management is also a concern on main county roads when there is a transition from a rural environment to a town or city.

Evaluating the Relationship between the Driver and Roadway to Address Rural Intersection Safety using the SHRP 2 Naturalistic Driving Study Data, RB05-013, 2016

Rural intersections account for 30% of crashes in rural areas and 6% of all fatal crashes, representing a significant but poorly understood safety problem. Transportation agencies have traditionally implemented countermeasures to address rural intersection crashes but frequently do not understand the dynamic interaction between the driver and roadway and the driver factors leading to these types of crashes. The Second Strategic Highway Research Program (SHRP 2) conducted a large-scale naturalistic driving study (NDS) using instrumented vehicles. The study has provided a significant amount of on-road driving data for a range of drivers. The present study utilizes the SHRP 2 NDS data as well as SHRP 2 Roadway Information Database (RID) data to observe driver behavior at rural intersections first hand using video, vehicle kinematics, and roadway data to determine how roadway, driver, environmental, and vehicle factors interact to affect driver safety at rural intersections. A model of driver braking behavior was developed using a dataset of vehicle activity traces for several rural stop-controlled intersections. The model was developed using the point at which a driver reacts to the upcoming intersection by initiating braking as its dependent variable, with the driver’s age, type and direction of turning movement, and countermeasure presence as independent variables. Countermeasures such as on-pavement signing and overhead flashing beacons were found to increase the braking point distance, a finding that provides insight into the countermeasures’ effect on safety at rural intersections. The results of this model can lead to better roadway design, more informed selection of traffic control and countermeasures, and targeted information that can inform policy decisions. Additionally, a model of gap acceptance was attempted but was ultimately not developed due to the small size of the dataset. However, a protocol for data reduction for a gap acceptance model was determined. This protocol can be utilized in future studies to develop a gap acceptance model that would provide additional insight into the roadway, vehicle, environmental, and driver factors that play a role in whether a driver accepts or rejects a gap.

Fast Track and Fast Track II - Cedar Rapids, Iowa, HR-544, Construction Report, 1989

Two lanes of a major four lane arterial street needed to be reconstructed in Cedar Rapids, Iowa. The traffic volumes and difficulty of detouring the traffic necessitated closure for construction be held to an absolute minimum. Closure of the intersections, even for one day, was not politically feasible. Therefore, Fast Track and Fast Track II was specified for the project. Fast Track concrete paving has been used successfully in Iowa since 1986. The mainline portion of the project was specified to be Fast Track and achieved the opening strength of 400 psi in less than twelve hours. The intersections were allowed to be closed between 6 PM and 6 AM. This could occur twice - once to remove the old pavement and place the base and temporary surface and the second time to pave and cure the new concrete. The contractor was able to meet these restrictions. The Fast Track II used in the intersections achieved the opening strength of 350 psi in six to seven hours. Two test sections were selected in the mainline Fast Track and two intersections were chosen to test the Fast Tract II. Both flexural and compression specimens were tested. Pulse velocity tests were conducted on the pavement and test specimens. Maturity curves were developed through monitoring of the temperatures. Correlations were performed between the maturity and pulse velocity and the flexural strengths. The project was successful in establishing the feasibility of construction at night, with no disruption of traffic in the daytime, using fast Track II. Both the Fast Track II pavements were performing well four years after construction.

Resource-based approach to new product development at the intersection of industries. Two case studies in telecommunications

Työn tavoitteena on selvittää mitkä ovat tärkeimmät aineettomat resurssit, joita tarvitaan teollisuuksien risteyskohdassa tapahtuvassa tuotekehityksessä. Teollisuuksien risteyskohdissa syntyvät tuotteet ovat usein radikaaleja, mikä tekee tuotteista mielenkiintoisia, paljon liiketoimintapotentiaalia tarjoavia. Tämä tutkimus lähestyy tuotekehitystä resurssipohjaisesta näkökulmasta. Myös tietämyspohjaista ja suhdepohjaista näkemystä hyödynnetään korostamaan keskittymistä aineettomiin resursseihin. Tutkimuksessa rakennetaan viitekehys, jossa tutkitaan eri resurssikategorioita. Valitut kategoriat ovat teknologiset, markkinointi-, johtamiseen ja hallinnointiin liittyvät ja suhdepohjaiset resurssit. Empiirisessä osassa tutkitaan kahta uutta tuotekonseptia, jotka ovat syntyneet teollisuuksien risteyskohdissa. Empiirisen osan tavoitteena on määritellä tutkimuksen kohteena olevia alustavia tuotekonsepteja tarkemmin ja selvittää millaisia resursseja näiden toteuttamiseen tarvitaan. Myös tarvittavien resurssien nykytila selvitetään ja pohditaan tulisiko puuttuvia resursseja kehittää yrityksen sisällä vai hankkia ne ulkopuolelta. Tutkimus toteutettiin asiantuntijahaastatteluin. Kahden tapaustutkimuksen perusteella näyttäisi siltä, että suhdepohjaiset resurssit ovat erittäin tärkeitä teollisuuksien risteyskohdissa tapahtuvassa tuotekehityksessä. Myös teknologiset resurssit ovat tärkeitä. Markkinointiresurssien tärkeys riippuu lopullisesta tuotekonseptista, kun taas johtamiseen ja kehittämiseen liittyvät resurssit ovat tärkeitänäiden konseptien luomisessa.