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EXCELLENCE in MULTI-MODAL TRAFFIC ENGINEERING and PLANNING TODAY
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PRISM Engineering Expert Witness Services are thorough and complete engineering reviews of traffic and design situations, complete with Declarations, Depositions, and Court Testimony. 
Traffic SAFETY. It is an official CEQA Environmental Impact.
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Some say Level of Service (LOS) is Dead. Its Not.
Here's why LOS is more important than ever---a case study in Pasadena, CA
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City of Pasadena, CA. Traffic Engineer chasing LOS F conditions, live.
PRISM Engineering was hired recently to study traffic in Pasadena, CA. Here is one of many surveys taken by PRISM in Feb 2020.
Traffic Conditions in Pasadena, CA like so many other cities in California, keeps getting worse as traffic continues to grow, and mitigations of major projects instead focus on providing bike and pedestrian facilities. Such is the consequence of using only Vehicle Miles Traveled (VMT) instead of Level of Service (LOS) to measure traffic impacts. ... Safety has been COMPROMISED.
(continue reading below, expand box...)
LOS is actually related to safety.... (cont.)
LOS MEASURES THE MOVEMENT OF VEHICLES, AND IS ACTUALLY RELATED TO SAFETY.
VMT has no relationship to safety, at all. However, LOS is a measurement of congestion and delay, and these two factors have much to do with safety and accident rates on the rise. More drivers take chances when they are delayed. The transportation systems need to address this majority component of traffic, not ignore it and let it fester.
This optional VMT related change gives "IN-FILL" development a "pass" on being accountable for real traffic impacts and congestion on the roads, because it happens to be a high density skyscraper, which is deemed good for the environment, even if it isn't. The fact is, skyscrapers with their very tall presence on a small footprint generates a lot more traffic than a shorter building. Vehicle traffic impacts continues to matters, even if many cities choose to ignore the constant vehicle growth. Ignoring traffic impacts while the accidents rates get worse and there is a rising number of vehicle collisions year by year. As a result, Safety has been COMPROMISED.
The Complete Streets Act of 2008 in California, requires that Cities and Counties and Caltrans to have a transportation network that meets the needs of ALL users of streets, roads, and highways, defined to include:
MOTORISTS, PEDS, BIKES, TRANSIT etc. Note that "MOTORISTS" are included in the law. These can NOT be ignored, or "de-emphasized."
Many cities in California have been focusing on Complete Streets concepts and taking away needed lanes from vehicle traffic to make room for bike lanes, TWLTL*, and pedestrian facilities, or transit. Some have dubbed it "de-emphasizing" the street. "De-emphasizing intersection LOS." Adding a light rail, for instance, can impact vehicle flows significantly, as can be seen several times in this video. This is because the light-rail is "at-grade" and the gates come down and completely block traffic flows in all directions. When traffic conditions are nearing capacity, as they are in this video, solutions that examine the traffic operations as a whole are needed, since a cursory calculation of LOS at a single intersection is insufficient to identify the real problems. An intersection may calculate at LOS C for instance, the average of all four approaches, but there may be an LOS F condition for one of the approaches that affects the surrounding streets in addition to the intersection. When traffic has to wait more than one signal cycle, that traffic is at LOS F conditions. This is because it only takes 80 seconds of delay to meet the LOS F threshold. Most signal cycles are at least 80 seconds long, so if you miss the green light time, and have to wait even longer, you are going to be at the unacceptable LOS F condition. This video shot and narrated by California registered Traffic Engineer Grant Johnson, shows many locations in this situation. Take a look.
*TWLTL=Two-way left turn lane, sometimes referred to as a "suicide lane" in the middle of a road
VMT has no relationship to safety, at all. However, LOS is a measurement of congestion and delay, and these two factors have much to do with safety and accident rates on the rise. More drivers take chances when they are delayed. The transportation systems need to address this majority component of traffic, not ignore it and let it fester.
This optional VMT related change gives "IN-FILL" development a "pass" on being accountable for real traffic impacts and congestion on the roads, because it happens to be a high density skyscraper, which is deemed good for the environment, even if it isn't. The fact is, skyscrapers with their very tall presence on a small footprint generates a lot more traffic than a shorter building. Vehicle traffic impacts continues to matters, even if many cities choose to ignore the constant vehicle growth. Ignoring traffic impacts while the accidents rates get worse and there is a rising number of vehicle collisions year by year. As a result, Safety has been COMPROMISED.
The Complete Streets Act of 2008 in California, requires that Cities and Counties and Caltrans to have a transportation network that meets the needs of ALL users of streets, roads, and highways, defined to include:
MOTORISTS, PEDS, BIKES, TRANSIT etc. Note that "MOTORISTS" are included in the law. These can NOT be ignored, or "de-emphasized."
Many cities in California have been focusing on Complete Streets concepts and taking away needed lanes from vehicle traffic to make room for bike lanes, TWLTL*, and pedestrian facilities, or transit. Some have dubbed it "de-emphasizing" the street. "De-emphasizing intersection LOS." Adding a light rail, for instance, can impact vehicle flows significantly, as can be seen several times in this video. This is because the light-rail is "at-grade" and the gates come down and completely block traffic flows in all directions. When traffic conditions are nearing capacity, as they are in this video, solutions that examine the traffic operations as a whole are needed, since a cursory calculation of LOS at a single intersection is insufficient to identify the real problems. An intersection may calculate at LOS C for instance, the average of all four approaches, but there may be an LOS F condition for one of the approaches that affects the surrounding streets in addition to the intersection. When traffic has to wait more than one signal cycle, that traffic is at LOS F conditions. This is because it only takes 80 seconds of delay to meet the LOS F threshold. Most signal cycles are at least 80 seconds long, so if you miss the green light time, and have to wait even longer, you are going to be at the unacceptable LOS F condition. This video shot and narrated by California registered Traffic Engineer Grant Johnson, shows many locations in this situation. Take a look.
*TWLTL=Two-way left turn lane, sometimes referred to as a "suicide lane" in the middle of a road
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A great experiment has been taking place throughout the world, but especially in California, to get people out of their cars and riding bikes or walking on the sidewalks. It sounds really nice, but in the United States...there is a very deep rooted car culture. Level of Service (LOS) still matters.
Drivers want LOS C or better conditions, but instead they are getting LOS F.
Traffic Engineering has been criticized by some planners, but it is so much more relevant today, than ever before. Rather than try to get people out of their cars, we should take care of those cars instead. LOS matters.
Watch to see what SB 743 in California has done to transform the state into a more congested traffic jam.
The California Complete Streets Act (Assembly Bill No. 1358, CHAPTER 657, An act to amend Sections 65040.2 and 65302 of the Government Code), requires Cities and Counties and Caltrans to have a transportation network that meets the needs of ALL users of streets, roads, and highways, defined to include:
MOTORISTS, PEDS, BIKES, etc. Note that "MOTORISTS" are included in the law. These can NOT be ignored. The Level of Service on a road even for vehicles needs to "meet the need" as per state law. General Plans need to reflect this.
Drivers want LOS C or better conditions, but instead they are getting LOS F.
Traffic Engineering has been criticized by some planners, but it is so much more relevant today, than ever before. Rather than try to get people out of their cars, we should take care of those cars instead. LOS matters.
Watch to see what SB 743 in California has done to transform the state into a more congested traffic jam.
The California Complete Streets Act (Assembly Bill No. 1358, CHAPTER 657, An act to amend Sections 65040.2 and 65302 of the Government Code), requires Cities and Counties and Caltrans to have a transportation network that meets the needs of ALL users of streets, roads, and highways, defined to include:
MOTORISTS, PEDS, BIKES, etc. Note that "MOTORISTS" are included in the law. These can NOT be ignored. The Level of Service on a road even for vehicles needs to "meet the need" as per state law. General Plans need to reflect this.
PRISM Engineering Designing solutions that will WORK to improve traffic flow (LOS C) and help save the environment with traffic-calmed modern roundabouts that slow speeds.
Transportation Solutions for the INTERIM
PRISM Engineering is expert at understanding the engineering side of traffic flow.
PRISM Engineering. Analyzing and optimizing traffic flows through signal timing and lane utilization at the intersection level.
All drivers want at least LOS C or better conditions.
Anything less is an aggravation in driving.
All drivers want at least LOS C or better conditions.
Anything less is an aggravation in driving.
California's High Speed Rail Woes. A train now, who's future build is a question mark. At an estimated cost of over $100,000,000,000 (that's $100 BILLION), this improvement did not match the need/demand. There are 1,857 miles of interstate freeways in CA today (I-5, I-8, I-40, I-80 etc), if reconstructed all over today using new materials, would cost much less at $6,000,000 per mile for a 6 lane rolling hills freeway, and so the total cost would be $6M x 1,857 miles = $11,140,000,000. Let that sink in. $11 Billion.
The proposed HSR would cost 9 times more than just building all BRAND NEW interstate freeways from the foundation up, throughout all of California. All new freeways, 10's of thousands of jobs, for 1/10 the cost of the HSR project.
costs source: https://www.fhwa.dot.gov/policy/2015cpr/appendixa.cfm
The proposed HSR would cost 9 times more than just building all BRAND NEW interstate freeways from the foundation up, throughout all of California. All new freeways, 10's of thousands of jobs, for 1/10 the cost of the HSR project.
costs source: https://www.fhwa.dot.gov/policy/2015cpr/appendixa.cfm
PRISM Engineering highlights HSR progress as of AUG 2019, in Central California on HSR location.
Fully Autonomous Vehicles on Redesigned Roadways with Grade Separations between Pedestrians and Vehicles is the Future Safety Solution that has been Elusive.
1.25 MILLION PEOPLE die each year in vehicle related accidents. 1.25 Million, each year! This default status quo is not acceptable. AV is the obvious near-term solution.
1.25 MILLION PEOPLE die each year in vehicle related accidents. 1.25 Million, each year! This default status quo is not acceptable. AV is the obvious near-term solution.
PRISM Engineering discusses why AUTONOMOUS VEHICLES are the answer.
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