Expert Witness SERVICES
grant johnson, te has worked on expert witness work
with numerous law firms over the past two decades
with numerous law firms over the past two decades
image credit: Photo by Taras Makarenko from Pexels
A Plaintiff Case. Grant P. Johnson, Traffic Engineer
looking north at the NB approach. Crest of hill blocks all view of striping and change in alignment. Signal heads are visible, but off to the right and not obvious to a first time driver.
DILEMMA ZONE, VERTICAL CURVE, HORIZONTAL CURVE, SIGNAL TIMING CONFUSION, HIGH SPEEDS, ADVANCE WARNING MISSING, NOT FOLLOWING GUIDELINES
THIS INTERSECTION DOES NOT MEET PROFESSIONAL STANDARDS as established by the MUTCD, AASHTO Green Book, etc.
THIS INTERSECTION DOES NOT MEET PROFESSIONAL STANDARDS as established by the MUTCD, AASHTO Green Book, etc.
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The subject intersection, as currently designed and traffic control devices installed, does not meet professional standards without an advance warning sign or system in place. There are several reasons for coming to this conclusion, and each of these will be explained in the paragraphs that follow:
1) The high speeds of the road (55 mph speed limit posted) coupled with 2) A change in vertical and 3) A change in alignment or horizontal curve after the crest which keeps this change invisible until just 300 feet before the intersection. This can and does cause confusion especially when approaching the signalized intersection at high speeds, causing driver dilemma. We took aerial photos of the intersection and northbound 55 mph approach, and found nine significantly long skid marks before and continuing after the crest of the hill. 
Some engineers are saying that they can see the cross bar (mast arm) of the NB approach signal, along with all of the signal heads, which is true, but it is important to note from a traffic engineering standpoint that these signal poles are only partially seen and that they are significantly offset from the NB approach alignment so as to possibly give the perception that they do not apply. The left turn lane signal head is aligned over the bike lane, the #1 lane signal head is aligned over the bike lane, and the #2 signal head is aligned over the right turn pocket. A driver should not have to analyze an unseen intersection and how signal poles rising up over a crest of road apply to whom. It is too much information to process and at high speeds can be dangerous.
In the paragraphs below, I show aerial photos of the same location where skid marks are found and there are a total of nine skid marks as of the day of my field visit, which was April 25, 2018. In the graphics prepared below, the skid mark locations are highlighted with red lines to show their location and the extent of how long these skids were. In my view, this is a lot of skid marks in a dilemma zone not necessarily caused by signal timing, but a perfect storm of compounded unsafe conditions which include: 1) Driver can not see lane striping over the crest, so they don't know their path will shift significantly to the right, 2) Driver can't perceive intersection shape or how the signal poles fit into the bigger picture because they can't see the bigger picture, 3) Speeds are very high at 55 mph and drivers are traveling even faster in the 85th percentile (57-58 mph for NB traffic), 4) no advance warning was given to drivers that there is a signal ahead, that they may need to stop, and so we see the result of that being several very long skid marks. The Mountain View highway was originally set with a 45 mph speed limit, and then in 2013 UDOT (Exhibit 50) they changed it to 55 based on the prevailing speeds 85th percentile of 57 mph. Once the speeds were set higher, the challenge to stop a vehicle at a red light becomes even more difficult. |
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The MUTCD supports the contention that if there are visual obstructions in the roadway (such as the vertical curve and crest of the road obscuring striping and traffic control devices in any way), or if visibility is limited due to changes in roadway alignment, that Advance Traffic Control signs should be used according to typical placement as shown in the MUTCD. These signs include the Stop Ahead (W3-1), Yield Ahead (W3-2), and Signal Ahead (W3-3) signs. Even if there are not these permanent obstructions, the MUTCD also provides guidance for even intermittent obstructions (such as parked vehicles, or foliage), and states that engineering judgment should determine the treatment to be implemented.
SUPPORT for ADVANCE warning signs and beacons
Section 2C.36 Advance Traffic Control Signs (W3-1, W3-2, W3-3, W3-4) Standard: 01 The Advance Traffic Control symbol signs (see Figure 2C-6) include the Stop Ahead (W3-1), Yield Ahead (W3-2), and Signal Ahead (W3-3) signs. These signs shall be installed on an approach to a primary traffic control device that is not visible for a sufficient distance to permit the road user to respond to the device (see Table 2C-4). The visibility criteria for a traffic control signal shall be based on having a continuous view of at least two signal faces for the distance specified in Table 4D-2. Support: 02 Figure 2A-4 shows the typical placement of an Advance Traffic Control sign. 03 Permanent obstructions causing the limited visibility might include ROADWAY ALIGNMENT or structures. Intermittent obstructions might include foliage or parked vehicles. Guidance: 04 Where intermittent obstructions occur, engineering judgment should determine the treatment to be implemented. Option: 05 An Advance Traffic Control sign may be used for additional emphasis of the primary traffic control device, even when the visibility distance to the device is satisfactory. 06 An advance street name plaque (see Section 2C.58) may be installed above or below an Advance Traffic Control sign. 07 A warning beacon may be used with an Advance Traffic Control sign. 07a A BE PREPARED TO STOP (W3-4) sign (see Figure 2C-6) may be used in advance of a traffic control device that could require motorists to stop, such as a traffic control signal or a STOP sign. 08 A BE PREPARED TO STOP (W3-4) sign (see Figure 2C-6) WATCH FOR STOPPED VEHICLES (SW60(CA)) sign (see Figure 2C-6(CA)) may be used to warn motorists of stopped traffic caused by a traffic control signal or such as in advance of a section of roadway that regularly experiences traffic congestion. |
OPINION 2: THEY SHOULD HAVE CONSIDERED INSTALLATION OF AN AWS (ADVANCE WARNING SYSTEM)
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As a default, AWS should be considered for every intersection, and then ruled out if it does not meet the criteria or pass the engineering judgment test. In the case of this intersection, there were clearly sight distance issues for the NB approach vertical curve and the NB approach horizontal curve / change in alignment AFTER the crest of the hill (therefore it could not be seen that the road will shift in alignment just a few hundred feet before the intersection, not enough time to react at 55+ mph speeds if the signal changes to red). The crest of the hill and the change in alignment are two sight distance factors for vertical and horizontal curves combined, and an engineer would know that this is a situation that requires due attention. Since these factors can not be removed, then according to the UDOT AWS criteria chart (seen at right), the roadway speed is the final deciding factor if the 85th or posted speed is greater than 45 mph. It is, and the result should have been to install the AWS.
The UDOT AWS chart also emphasizes that if sight distance is not considered an issue, they wanted to first see a severe crash history before taking action to put in an AWS. Expand chart to the left to see details of this. |
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It can not be reasonably argued that vertical and horizontal sight distance was not an issue on the northbound approach, just because it was possible to see a portion of the signal mast arm from a long distance away. The crest of the approach prevents the driver from seeing the striping and corresponding change in alignment/direction of travel. To the first time driver, this would come as a complete surprise, and it would not be obvious that the road changes in alignment. It would also not be obvious to the first time driver that with all of the street lights
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The UDOT document SIGNALIZED INTERSECTION DESIGN GUIDELINES, January 2017 states in Section 7 on Page 57:
"An advance warning signal (AWS) may be warranted in association with high-speed signalized intersections to warn drivers in advance of the end-of-green phase approaching the signalized intersection. The warranting process for an AWS is found in the AWS Guidelines... AWS systems are not necessary or appropriate at all signalized intersections as they may contribute to over-signing and will lose their effectiveness if they are overused. Warranting for AWS systems ... follows the AWS Guidelines flow chart. This chart takes into consideration the following warranting criteria: limited sight distance, posted speed limit, history of severe crashes, whether the intersection is isolated from other intersections, heavy vehicle traffic, and approach grade." The AWS Guidelines flow chart is heavily favored to have AWS installed for intersections where there is a history of severe crashes, unless there is a sight distance issue. In the latter case an AWS is recommended for installation if the speeds are higher than 45 mph and there is no way to improve the sight distance problems. But in all other pathways on the flow chart, if there is not a high incidence of severe crashes, the chart does not recommend installation of AWS even if there is heavy traffic, steep approach grades, etc. The chart is biased towards a preference of letting severe crashes take place first, and then put in an AWS. This policy encourages engineers to put aside their "engineering judgment" and rely on a check list based on a financial consideration: the higher cost of installing a flashing signal beacon system versus not installing one unless there are first accidents. This is a problem with new installations because there will never be an accident history, and yet a dangerous condition could still exist at the location if not properly designed and supplemented with additional traffic engineering design and considerations of traffic control devices. These latter devices for traffic control require engineering judgment that is related to first ascertaining the roadway grades, the vertical and horizontal sight distance situation, the change of alignment in roads, blind spots for drivers trying to perceive an intersection that is out of sight because of a crest in the road, and the unexpected intersection that can not be seen from a distance due to sight distance constraints. At the subject intersection it is only possible to see several poles extending into the air, but the cross street and all relevant striping and traffic control at the intersection can not be seen by approaching drivers. Only the top of the street lights and signal mast arms can be seen, but they are not in line with the NB approach, but are off to the side because the roadway changes direction at the last portion only a few hundred feet away from the stop bar of the NB approach. This can not be seen until the car or truck is within only a few hundred feet. These problems could have been seen by an engineer exercising engineering judgment, and taking a test drive through the roadway system as a check before opening it to the public. |
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The National Society of Professional Engineers has written about this topic, the dilemma that many professional engineers face that discourages them to exercise "engineering judgment" for fear of retaliation or harm to their career or advancement, because of the political or financial pressures that may be in place to discourage an engineer from taking an ethical stand against what they feel is an unsafe condition or design flaw that ends up costing a lot of money to mitigate.
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Final Report of the NSPE Task Force on Overruling Engineering Judgment to the NSPE Board of Directors, June 30, 2006
https://www.nspe.org/sites/default/files/resources/pdfs/Ethics/EthicsResources/EducPubs/OverrulingEngineeringJudgement.pdf DILEMMA: Engineers face an ethical dilemma when their engineering judgment on issues affecting public health or safety is being overruled by a supervisor or regulator who has no engineering credentials. Though engineers are obligated to speak up and vigorously defend public health and safety in such situations, they are painfully aware of the risk of retaliation from those challenged by their ethical stand. The consequences could include employment termination or even the ruination of their professional careers and reputations. The consequences on an engineering employer/company must also be considered. Many contemporary engineering projects and programs are now directed by non- engineers. During the latter half of the 20th century, many government agencies and corporations have focused on the non-technical aspects of technical programs in determining the qualifications of managers. Furthermore, many regulatory agencies exercise powerful control over the details of projects and programs owned or operated by others. Today, engineers sometimes report to political scientists, public administrators, and MBAs at the head of their organizations. Sometimes this structure works well, relieving the engineers of the non-technical problem areas but deferring to the engineer’s judgment on all technical issues. However, a risk that is frequently ignored is that, unless a trust relationship develops between the engineer and the non- engineer supervisor or regulator, the technical program or project can be misdirected into unstable and even dangerous ground that may become unduly influenced by political factors, public relations issues, financial considerations, and unreasonable completion schedules. It is important to realize that disasters caused by engineering failures, such as the Challenger and Columbia disasters, damage the careers of thousands of employees in the public and private sectors. It takes years to recover. Had the engineers been clearer, more assertive, and more persuasive in communicating life-threatening concerns to non-engineer managers in the Challenger and Columbia disasters; and, conversely, had the non-engineer and engineer managers understood the risks being taken by their failure to listen to the subordinate engineers, perhaps their decisions would have been different. |
OPINION 3: THE HUMP IN THE HILL BEFORE THE INTERSECTION CREATES A VERTICAL SIGHT DISTANCE ISSUE.
THE BEND IN ALIGNMENT AFTER THE HUMP CREATES ANOTHER HORIZONTAL SIGHT DISTANCE ISSUE
THE BEND IN ALIGNMENT AFTER THE HUMP CREATES ANOTHER HORIZONTAL SIGHT DISTANCE ISSUE
looking north at the NB approach. Crest of hill blocks all view of striping and change in alignment. Signal heads are visible, but off to the right and not obvious to a first time driver.
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looking south at the NB approach from intersection stop bar. The crest of hill is 250' away. This is the lane striping and change of direction drivers can not see when coming north.
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In the illustration to the left, sheets GR-13 by Horrocks Engineers and GR-14 by Lochner, were composited into a single sheet to show the relevant sections of the NB approach to the Rosecrest Road intersection as well as the Rosecrest Road intersection when it was initially a T-intersection only. This illustration is important, because it shows how the fill was built up unnecessarily to a crest at Station 3157+50 elevation 4927 contour line, and then sloping back down to the elevation at Rosecrest Road which shows on the plans as 4922, or about a 5 foot drop in elevation after the crest (over a 300 foot distance). If this crest was not constructed as it was, if the road surface elevation of the NB approach never exceeded 4922, there would be no sight distance issues, vertical or horizontal. Since the highest existing grade elevation was 4918 at Station 3153+60, there was an easy ability to design the road to have no vertical crest.
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Since the road was designed and constructed without vertical sight distance constraints in mind that would have been an issue for an intersection (Rosecrest Road to be added in later), there was a responsibility on the engineers who, installing a new intersection with full four-way signalization, to take a close look and examine all traffic engineering and safety factors including measuring vertical and horizontal sight distance constraints, examining stopping speeds, examining the lack of visual on lane striping on a change in alignment, and whether the signal could be typically seen (since it was offset from approach alignment, depending on lane, and signal heads did not align with roadway lanes until at a point only approximately 250 feet from the stop bar at the intersection). It is my view that because of the change in alignment, and because the change in alignment could not be seen by any driver until at a point approximately 300 feet away from the stop bar, it would be impossible for a driver to ascertain from a distance greater than 300 feet whether the signal heads in the foreground, if seen, actually applied to their movement or not. This is why it is so important that the lanes and striping be seen by a driver as they give reference to the traffic control device ahead and which lanes the signal heads apply to.
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OPINION 4: PROFESSIONAL ENGINEERS SHOULD HAVE TESTED THE ROADWAY FOR SAFETY CONSIDERATIONS BEFORE THEY OPENED IT
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A test drive should have been performed at this location before it was opened to the public. There are several factors that should have been considered or investigated before opening to the pubic. These include:
1) Change in direction of alignment after the hill crest, 2) Vertical crest sight distance constraints for seeing striping as well as the intersection and change in alignment direction, 3) Effective signal perception since the poles and mast arms are not in line with the roadway alignment coming up the hill of the NB approach, 4) Higher speeds of traffic because speed limit was raised from 45 mph to 55 mph, 5) Lack of any signal ahead signage or warning lights. I personally did a test drive with a typical small SUV vehicle, and drove at a speed of 55 mph on the NB approach to the subject intersection accident location, Rosecrest Road at Mountain View Highway (SR 85). I drove in the fast lane and as I approached the crest of the hill I could not see the intersection ahead. It was obscured by vertical crest sight distance constraints, and was not visible until I was approximately 300 feet away from the intersection. Traveling at 55 mph, I suddenly noticed that the alignment of the road had changed and my vehicle was headed directly into the left turn pocket at Rosecrest Road. I slowed down as quick as possible for the red light finding myself in the left turn pocket. |
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On a subsequent pass through the intersection headed northbound, I measured the curve impact at the same location making sure to stay in the #1 lane this time, and by using a Ball-Bank reader (a device that mounts to the dash and measures if a vehicle is experiencing tilt to the left or right in a turn (see picture of "Lev-o-gage" we used in this test, shown at right)), I measured the tilt of the vehicle to maintain inside the lane. A video camera recorded the ball bank reader, where a small black ball moves slowly through a liquid, measuring how many degrees of tilt deflection the vehicle makes from a level state while navigating the curve. A turn to the right would cause the black ball to move to the left. The MUTCD stipulates that if a ball bank measurement exceeds 12 points on the tilt scale, then warning signs are appropriate to warn the driver of a suggested reduced speed.
The vertical sight distance at the crest eliminates the ability of a driver to actually see the lane striping ahead of the crest. This is an important problem, because the driver has to focus more on the lane striping and staying in one's lane, at high speed, and may have their attention diverted away from noticing the traffic signal condition (may not notice if it changes from green to red, for instance). In this case, the flashing yellow beacons would certainly provide an advance visual warning that can be easily understood to the driver, since the signals ahead in this case are offset from the NB approach alignment and do not straddle the through lanes, the driver's perception of their location is that they are off to the right and that only the tops of the poles can be seen. It is not a clear picture for perception, and driver perception matters to how fast a driver can process what they see and make an appropriate reaction. The total stopping time for a driver consists of three parts: 1) perception, 2) reaction, and 3) Braking. If the first part takes too long or is not noticed because it is only partially seen and not seen in the normal context of what a driver is used to seeing, then the total stopping time is increased. This is precisely the reason that the flashing yellow beacon was invented, to provide drivers a better perception that a dilemma zone exists ahead, and they need to pay more attention and possibly slow down. |
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SAFETY. Above all else, Safety is the first priority with Grant Johnson, Traffic Engineer, who is regularly examining the safety of transportation systems and traffic control devices... to determine if the installations are safe, normal, and customary. Was common sense used? He can help you on your next case to determine if a traffic control installation is / was standard according to AASHTO, MUTCD, State and Local Standard Plans, etc., or if there was an error made which contributed to an accident. |
An extension of Traffic Engineering, Expert Witness research and testimony are about intimate knowledge of the regulations and details, documentation, and precedent.
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Grant P. Johnson, TE is a registered Traffic Engineer in the State of California, the only state in the union with this special distinction. Now a requirement of many government jurisdictions to qualify traffic studies, the Traffic Engineer is being asked to sign documents as an authority on the subject of all things pertaining to traffic and regulation. In Expert Witness testimony and research, the title of Traffic Engineer enhances credibility.
Mr. Johnson is currently working on several Expert Witness cases in California including multiple Bay Area Cities, as well as Southern California cities and counties. |
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Working with the United States Attorney's Office in the Department of Justice, Mr. Johnson was retained to perform Expert Witness Traffic Engineering review of an accident case, including field review, examination of roadway traffic control devices and compliance with relevant Federal documents such as MUTCD*. *MUTCD=Manual of Uniform Traffic Control Devices, FHWA |
photo/video © 2019 PRISM Engineering
Grant Johnson, TE, has extensive experience designing traffic signal plans including equipment placement, conduit and electrical systems, as well as all signing and striping relating to intersection control.
He can review existing signal plans and determine if the signal meets standard plans, and whether signing and striping was properly installed. He can also determine adequacy of advance detector systems, flashing beacons, etc., and especially as these various traffic control devices comply with your state's MUTCD and other Highway Design standards of safe stopping sight distance, etc.
He can review existing signal plans and determine if the signal meets standard plans, and whether signing and striping was properly installed. He can also determine adequacy of advance detector systems, flashing beacons, etc., and especially as these various traffic control devices comply with your state's MUTCD and other Highway Design standards of safe stopping sight distance, etc.
SIGNAL DESIGN and REVIEW of INSTALLATIONExample of Expert Witness work: Detailed examination of intersection and signal installations from aerials, plan sheets, and site inspection, by PRISM Engineering
PRISM Engineering reviews field conditions using high definition aerial photos, correlates this to plans, and examines to scale, locations of skid marks, striping, and pole installations, etc. in relation to the intersection. photo/video © 2019 PRISM Engineering |
INTERSECTION EXAMINATION of TRAFFIC CONTROLPRISM Engineering understands the standards relating to proper and improper traffic control device installations, including signals, poles, signing and striping, as they relate to the guidance in the MUTCD*, the AASHTO Green Book, FHWA**, Highway Design Manuals, and Engineering Judgment. *Manual of Uniform Traffic Control Devices **Federal Highway Administration photo/video © 2019 PRISM Engineering |
EXAMPLE OF SIGNAL DESIGN WORK: El Dorado Hills Green Valley Road Corridor Signal and Interconnect Design by PRISM Engineering
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In this On-Call Services work order, PRISM Engineering worked directly with El Dorado County Department of Transportation Design Staff to create the signal design layers in the extensive AutoCAD design file with XREF overlays. Grant Johnson, TE was project manager of this work effort and designed the conduit runs, pole and detector locations, signal phasing and diagrams, signing and striping. |
PRISM Engineering has completed numerous signal design projects over the years, and integrated these plans with development applications where street and intersection improvements are required as a part of a traffic impact analysis. PRISM has the ability to take things from the planning stage of forecasting traffic, to the analysis stage of determining intersection and road segment improvements, and warranting of traffic signals for a new installation, or the modification of an existing signal expanded to include more lanes, etc. We have also designed inter-connected signal installations where traffic volumes between intersections are coordinated with offset signal cycle timings, and analyzed using SynchroPro and SimTraffic microsimulation.
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In this case he spoke before the Marin County Board of Supervisors on a hotly contested and controversial topic and discussed the traffic operations study results, and how information was shared with Caltrans, etc. Remaining low-key, stick to the facts mingled with common sense, and avoid contention. |
Grant Johnson, TE has extensive experience in making public presentations on technical topics, and in making them understandable and credible. 
Link to local newspaper story on this BOS decision and process: story: http://www.marinij.com/article/NO/20160413/NEWS/160419920 |
PUBLIC PRESENTATIONS, sample from San Francisco Bay Area
TRAIN CROSSINGS
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Train crossings can be considered with two different perspectives: A perfect and fully funded world where all signals and gates with flashing lights work flawlessly, and were perfectly designed (giving DRIVERS, BIKES and PEDS an expectation of safety), or in a less perfect but real world where rail road crossings exist but only have basic signals and gates, or even just a simple RR XING Warning Sign to warn the drivers they are crossing a track, and there are no gates and lights (typical of some rural conditions). Standards, safety goals and installation methods vary from jurisdiction to jurisdiction, situation to situation, and there is not a one-size-fits-all solution. There are manuals and standards that address different situations.
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DRIVERS EXPECTATIONS at RR XINGMany accidents can be traced to a scenario where a driver was met with an unexpected situation, or where they were suddenly surprised and did not know how to respond in time to avoid an accident. In the video below, the highly unlikely scenario where a Chicago rail road gate timer was so badly off, that the gates lowered completely AFTER the train already had passed through at high speed. Three cars narrowly missed getting hit by the train. PEDESTRIAN EXPECTATIONS at RR XING |
Imagine a signal installation or train crossing where the drivers think they are safe to cross or move forward, but for malfunction of a gate or signal, people's lives are put at risk. Fortunately in this case all three drivers of different cars survived missing the high speed train, a highly likely fatal situation. |
What responsibility to pedestrians have when crossing a railroad track? Should they wear headphones with loud volume so that they can not HEAR a train? What about the blind, who can't see but can hear the train? Are flashing signals, chirping audio sounds, the lowering gates, the ringing bells, and the sound of a roaring train approaching sufficient to protect the blind pedestrian, let alone the other pedestrians, riders of bikes, and drivers of vehicles who should be aware while using the transportation facilities? How much protection is too much, and how does this relate to "expectations?"
photo/video © 2019 PRISM Engineering
PRISM Engineering conducts Expert Witness consulting work in the following areas:
Using the guidance and regulation contained in the AASHTO, MUTCD, and State and Local Standard Plans and manuals, Grant Johnson, TE can review any traffic control device installation including signs, striping, pavement markings, sight distance with grades and curves and obstructions, etc., to determine compliance with accepted standards and engineering judgment. Examples follow:
Collision History Diagrams and Analysis.
PRISM Engineering identifies Crash Patterns through research and an analysis of the crash data on record for specific locations. To do this we create a collision diagram (see image to right), make a collision summary, conduct field reviews, etc. to obtain all relevant information possible.
PRISM creates a summary table of the crashes that occurred during the study period, and shows pavement conditions, crash type, lighting conditions, number of injuries or fatalities, and any other relevant information, such as driver-related facts (i.e., age, gender, restraint use). This makes it very useful to identify crash patterns. |
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Examination of Traffic Control Installations; Recommendations for Safety Enhancement, Intersection Design and Layout, Signal Design / Timings and Operations, Crosswalk Locations and Warnings, Railroad Pre-emption, Speed Limits, Pavement Delineation, School Areas and Traffic Control, Curve Warning Signage and Roadway Conditions, etc.
Guard Rails and Embankments, Curves, Bridges. Median Barriers, etc.
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Guardrail installations can be complex.
The decision on whether to install one depends on a number of factors of safety and engineering including,
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Sight Distance Studies and Analysis
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Stopping sight distance: the distance needed for drivers to see an object on the roadway ahead and bring their vehicles to safe stop in time before colliding with the object. We analyze these parameters based on speeds traveled and specific geometry of the road and any visual obstacles in place.
PRISM Engineering understands AASHTO, FHWA, and MUTCD standards for traffic safety and roadway standards, including standard plans compatible signal design and installation.
Construction Area Traffic Control Examination, Temporary Traffic Control, Long Term Traffic Control
PRISM Engineering also has expertise in: |
PRISM Engineering can review the adequacy of traffic control plans used by a City or County during construction projects. Traffic control planning requires forethought. Provisions may be incorporated into the project bid documents that enable contractors to develop alternate traffic control plans, which may be used only if the responsible agency finds they are as good as those provided in the plans/specifications. For maintenance and minor utility projects that do not require bidding, forethought must be given to selecting the best traffic control before occupying the temporary traffic control zone. Also, coordination must be made between projects to ensure that duplicate signing is not used and to ensure compatibility of traffic control between adjacent projects. (MUTCD, OSHA, CALTRANS, etc)
PRISM Engineering is familiar with the detailed MUTCD manual, which defines the standards used by road managers nationwide to install and maintain traffic control devices on all public streets, highways, bikeways, and private roads open to public travel. The MUTCD is published by the Federal Highway Administration (FHWA) under 23 Code of Federal Regulations (CFR), Part 655, Subpart F. States must adopt the National MUTCD as their legal State standard for traffic control devices. |
Pavement Conditions. Access Management. Parking Lot Layout. Street Lighting. Light Rail.
Depositions, Court Testimony
Expert Witness rate sheet available upon formal request ...
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