Bringing this all full circle and continuing my research of stop signs here as well as other traffic systems in comparison to the U.S., I have found that stop signs are a much larger issue than I had originally thought. Turns out some interesting work has been done to research ways to make roads safer while not obfuscating the driving space.

One major argument against stop signs is that the sheer number of stops signs decreases their effectiveness as drivers become somewhat “immune” to them and begin ignoring wayfinding instructions when they feel that following the signs would cost them time without actually preventing a collision, such as the case when a driver will not stop at a stop sign when no one else is around.

This is the main problem when stop signs are installed to arbitrarily interrupt traffic for speed control. In this case, the stop sign is intended to be an inconvenience to motorists, which it successfully achieves. The signs try to get motorists to slow down or switch routes. However, studies from across the U.S. have shown a high number of drivers ignoring stop signs when the signs are deliberately installed as “nuisances” or “speed breakers” with no other function at a specific intersection. After drivers reduce their speed in the immediate vicinity of the “nuisance” stop sign, they actually speed up between intersections to make up for lost time. Traffic calming devices, not stop signs, are much more effective tools. This is where the argument for British-inspired roundabouts and other road design solutions can play a part in maintaining traffic flow while reducing overall, average speeds in an area. Rather than stop signs designed to tell drivers, bicyclists and pedestrians who has the right-of-way, perhaps other options should be explored to help each group travelling different directions slow down, recognize and yield to one another, and continue on.

As suggested by several experts, nationally recognized standards established by the MUTCD based on traffic conditions and sight distance could be a plausible way to determine where stop signs should be used and where new solutions could be placed. Gary Lauder, a venture capitalist from Silicon Valley, just recently suggested a concept he has been working on for some time that would be a new wayfinding sign design as a mixture of a stop sign and a yield sign. The actual presentation and design of his “Take Turns” sign requires plenty of work, but the thought is there and well-developed. Lauder described his idea in under five minutes at a TED conference. He explained that his new roadside symbol could take the place of some stop signs and, in certain circumstances, avoid unnecessary stops. Preventing the need to stop at empty intersections can actually save time, money and fuel while reducing carbon emissions and improving traffic flow. He estimated that one conventional stop sign at a T-intersection of a busy road and a smaller road costs about $112,000 a year in fuel and lost time. His argument is that the sign is wasteful and no longer safe, and when drivers catch on to this, it “turns otherwise honest citizens into lawbreakers.”

Watch the video below, visit the page on, and read the CNN interview with Lauder. Tell me what you think. What should Iwasaki and Caltrans do?


I touched on this a bit with my last post, but I feel like one sign many common drivers have experience and frustrations with is the stop sign, which is used to assign right-of-way at a variety of intersections. Since stop signs do cause inconvenience for drivers, they should only be used where warranted by the MUTCD and California Supplement (2003), which includes details for when single stops, two-way stops, and four-way (multi-way) stops are appropriate.

Many drivers likely think that stop signs are just something that Caltrans just throws up wherever it pleases. However, as has been the trend in this blog, the design of the roadscape is extremely important and engineers and designers alike have a set system in place for how stop signs should be installed.

Standard stop signs, the ones we are all familiar with, are solid red octagons with a white legend and border.

At intersections where all approaches must stop, a supplemental plaque, either “4-Way” or “All Way,” also solid red with a white legend and border, is used. If the number of approaches that must stop is 3 or more, then the number on that extra plaque should correspond to the actual number of roads or “legs” controlled by stop signs.

There are regulations for single stop signs to be on the right of the road, and two can be used on wide roadways or intersections for clarity. I hardly see two stop signs on wide roads, and I believe this could increase visibility and compliance. If two or more lanes approach a stop, at least one stop sign must be visible to each lane. Another regulation states that no signs other than the “Do Not Enter” sign can be mounted back-to-back with a stop sign because these other signs obscure the symbolic octagonal shape of the STOP sign. I am impressed to see semiotics in motion within Caltrans regulations!

Stop signs should be located as close as possible to the point where vehicles stop. At crosswalks, the signs appear in advance so drivers know to stop before they reach the crossing area. If the stop sign is installed at the required location and sign visibility is restricted, a “Stop Ahead” sign must be used in advance of the stop sign. This is extremely important, as I have mentioned before, to decrease reaction time and increase visibility so drivers understand their role on the road. I feel like I have seen several stop signs whose view is obstructed by trees, sharp turns, or other signs. The driving space must be cleared of these hazards and/or a Stop Ahead sign should be posted to increase safety and compliance. Further, I believe more stop signs should be supplemented with a stop line or the word “Stop” painted on the asphalt as is done in selected areas. If Caltrans Director Iwasaki made Caltrans take the time to maintain the space and viewing of stop signs and supplement them with on-the-road wayfinding symbols or instructions, drivers would notice and take the signs more seriously. My post about reflectivity comes into play here as well: part of maintenance is making sure signs are replaced according to their individual life cycles and tested for nighttime legibility according to reflectivity and clear roadways.

According to the Institute of Transportation Studies at UC Berkeley, the following could be considered to adjust the wayfinding at intersections where there is a history of drivers failing to heed a stop sign:

  1. Improve visibility or sight distance to the stop sign
  2. Install “Stop Ahead” sign
  3. Increase the size of stop and stop ahead signs from 30 to 36 inches
  4. Use a double-indicating left-side stop sign in addition to the right-side stop sign
  5. Install two transverse rumble strips (read about effectiveness of rumble strips) in the approach lane, one before the stop ahead and the other before the stop sign
  6. Install two additional transverse rumble strips to supplement the first two locations
  7. Install intersection illumination
  8. Add a flashing red beacon to the stop sign or an overhead intersection control beacon for all approaches of a four-way stop, or with flashing red for the minor street and flashing yellow for the major street at a two-way stop
  9. Place flashers on top of the stop sign, with flashers actuated by a detector in the pavement in advance of the stop sign.

I encourage Iwasaki to develop, among other programs, a Caltrans program to evaluate the effectiveness of stop signs and see what we can do to decrease the number of disregarded stop signs. By increasing compliance to road law, we can all drive safer because our driving habits will be more predictable and reliable.

I have been looking into some other blogs and publications about roadside wayfinding and have found quite a few examples of European standards that are worth exploring as options here in the U.S., specifically in California.

John Staddon’s article Distracting Miss Daisy in the July/August 2008 issue of The Atlantic Magazine raised several points that I think Caltrans could look into. Staddon, who has spent his professional life studying adaptive behavior of humans and animals according to changes in the environment, contends that as traffic signs have increased in sheer numbers in the U.S., drivers have adapted in unhealthy ways. He argues that a lifetime on the road trains drivers according to daily experiences. He says American reliance on signs and enforcement of following signs has taught U.S. drivers to follow signs alone without employing their judgment. In such a culture, he argues, states must keep adding more signs to tell drivers exactly when and how they need to adjust their driving. Otherwise, he says, drivers may see no reason why they should slow down on a curve in the rain or make any other obvious driving decision for themselves.

Although I am not sure I agree with Staddon’s argument that Americans are trained to rely only on signs rather than their intuition, I do agree that state and federal roadside signage has increased substantially to clarify messages that should have been clear on the original signs from the beginning This has a negative impact on the roadscape: everything appears cluttered. When so many signs are present, they all lose their impact.

Staddon goes on to suggest that the U.S. should adopt a system like the British traffic system, in which road wayfinding signs and signals are often on the road itself where drivers should be looking. As he explains, one British alternative to the stop sign is a simple dashed line on the pavement that signals the driver to yield rather than stop. The line tells the driver which road has the right of way and communicates all of this within the actual road space. Another method to slow traffic in Europe is the roundabout. Although the roundabouts drivers in the U.S. have seen are usually large, those in the U.K. have become smaller as drivers adapt to them over the course of a few decades. I think it is interesting that a “mini-roundabout” in the U.K. is essentially just a large white dot in the middle of an intersection that translates to an instruction for drivers give way to traffic coming from the other direction.

The concept of including wayfinding on the street, thus designing the driver’s path as a wayfinding tool in itself, is intriguing. This has the same advantage that the add-on exit number plates have on California’s interstates: all the information is displayed where the driver is looking anyway. This could help reduce car collisions in which drivers claim they could not see another car because they were distracted.

Although I do not agree with several arguments in Staddon’s article, I do agree that having road signs translated onto the asphalt has its advantages. This system is similar to what I mentioned back in my first post, with different color lines indicating different types of driving lanes and different strokes of lane lines indicating if and how the drivers can move from lane to lane. This use of specific semiotics and design decisions is easily recognizable for drivers now. With this lane line system already in place, drivers may be able to slowly adapt to the introduction of similar such tools as mini roundabouts or yield lines on the roads. If Caltrans and U.S. federal agencies could look into solutions similar to those utilized in the U.K., the U.S. could begin to expand its system of on-road wayfinding devices. Iwasaki could make a huge difference by bringing this about within Caltrans procedures. These systems are by far more cost effective and could save lives even if used in conjunction with current signage systems as another way to communicate to drivers. When combined with the use of Botts dots (which I love) and other methods of tactile wayfinding devices, these systems could definitely yield results and save lives.

If you want to read Staddon’s full article along with statistics on driving fatalities in the U.K. versus the U.S., read Distracting Miss Daisy.

Since I wrote the recent post about Clearview, I am more aware at night as to how type on signs is affected by overglow. I was astonished to find many signs that do not reflect well. For this reason, I believe another item to add to Caltran’s to-do list is to evaluate and improve the reflectivity of all highway and city street signs.

Some may ask why the reflectivity of a sign is something that concerns wayfinding or graphic design. Really, designers must consider all elements of each individual sign in order to build an effective wayfinding campaign. Elements like shape and material properties, if combined optimally, will help drivers see and understand where they are in time to react appropriately. Contrast, which is a measure of the brightness of the type on a sign against the sign’s background, is an important property of all signs. The environment surroundings of the driving space, including green foliage, blue sky and grey concrete, must also be considered to design signs that are visible in their natural setting.

In the case of reflectivity, the federally approved Manual on Uniform Traffic Control Devices (MUTCD) prescribes that all signs be either reflectorized or illuminated. California initially complied with this requirement by adhering reflective buttons onto existing, unreflecting sign copy. Although this worked well for awhile, the glue began to liquefy after 40 years of weather and created white streaks down the signs that made them look dirty and difficult to read.

Caltrans Director Iwasaki and his teams must understand that although nighttime traffic is less in volume than daytime traffic, the nighttime crash rate remains three times higher. Poor visibility of wayfinding devices is a contributing factor, so improving and maintaining sign reflectivity helps improve nighttime safety. Reflectivity affects every driver’s ability to read signs at night, but it is especially important for older drivers. In fact, a 59-year-old driver needs eight times more light than a 20-year-old driver to see the same object while driving.

There are regulations about reflectivity applicable to California, but it is evident that Caltrans has not been working to comply with these rules just yet. According to the Institute of Transportation Studies, minimum reflectivity levels are based on “currently available sign materials, vehicle headlight technology and height levels, and capabilities of the increasingly older driving population.” These minimum levels are specified in the FHWA publication Maintaining Traffic Sign Retroreflectivity (FHWA-SA-03-027).

The FHWA publication proposes guidelines to evaluate and maintain traffic sign reflectivity. Five methods to improve reflectivity of traffic signs are:

  1. visual nighttime inspections using calibrated signs,
  2. actual sign reflectivity levels measured using a retroreflectometer
  3. replacement based on individual sign life,
  4. blanket replacement of all signs in an area, and
  5. use of a sampling of control signs that represent field signs.

I understand that California is strapped for funds, so I suggest that Caltrans performs nighttime inspections and measurements of their current signage and replaces signs based on individual sign life rather than jump to a blanket replacement at this time. As I have seen for myself while driving at night in California, the reflectivity of wayfinding signs along the roadways gradually deteriorate over time. With this, it is vital that Caltrans monitors their highway and roadway signs and other devices and replace them before they cease to meet the needs of nighttime drivers. I argue that the issue is not whether the devices should ever be replaced, but instead when and how they should be replaced. The short answer is sooner than later. Caltrans has slacked so far, and they need to maintain their signage properly.

Following my last post about making California highways more legible to aid wayfinding, let’s talk about exit number signs. From early on, California has been known to take the cheapest way out on things such as wayfinding and road systems, so it is no surprise that something like exit signs has gone by the wayside in Caltran’s priority list and budget. As a visitor to the state, I have noticed that exit signs vary from county to county, and it confuses both me and my Garmin.

In 1970, the Federal Highway Administration (FHWA) required exit numbers along the interstate system, following either a mile-based or consecutive numbering method. The Manual of Uniform Traffic Control Devices (MUTCD) encouraged use of mileposts and exit numbering by 1961 and mandated exit numbering in 1971. At that time, however, California had already designed and built most of its interstate freeways, and it applied for and received a waiver from the mandate citing the cost of installing and maintaining additional signage. Then, February 2002 brought about the California Numbered Exit Uniform System (Cal-NExUS), which is Caltrans’s program for numbering California’s freeway exits. In theory, the system assigns exit numbers south-to-north and west-to-east on a mile-based system, where each exit is numbered according to how far it is from the highway’s south- or west-most limit.

 This was a great plan. According to Cal-NExUS Director Jeff Morales, “Numbering exits will help travelers find their way in areas unfamiliar to them, determine distances and travel mileage. The new signs will be much more visible at night and thus increase highway safety.”

However, Caltrans’s efforts to cost costs has led to problems. Even where exit signs exist due to the Cal-NExUS initiative, they are inconsistent from a wayfinding and design perspective. In most cases, the exit numbers and letters on signs posted before drivers reach the offramps are not listed at all. Instead, exit numbers are listed right as drivers are directly approaching the actual exit, making the numbering system ineffective because drivers cannot anticipate an exit coming up by anything other than the name of the exit. For those signs that do include exit numbers, they are listed differently than exits in other states in order to save money, according to Caltrans. Instead of being on exit tabs like in many other states, exit numbers are in the form of add-on plates on the large overhead sign denoting the name of the street exit, as authorized by California Sign Specification G85-11. The exit numbers are usually in the upper right-hand corner, separated from the rest of the sign composition by a rounded rectangle outline. Although I do think this is helpful for drivers who want to see all the information in one glance, its inconsistency with the rest of the U.S. freeways makes this design decision faulty.

The Cal-NexUS program did not receive much funding from the beginning. For the past several years, exits are only being signed with numbers when highway signage needs to be replaced. Unfortunately, Caltrans also has a history of not maintaining its road signage, and so signs that drivers may consider in need of a replacement may not be flagged for replacement by Caltrans for years. Originally, the initial completion date for this project was set as November 2004, and the deadline was then extended to 2008. However, the 2006 edition of the California MUTCD removed any sort of compliance deadline for the exit numbers, and it appears to have been completely erased within Caltrans’s to-do list. In fact, the original memorandum that deleted the compliance date is listed on Caltrans’s website.

Because the interstate system in California is so expansive, perhaps it would be best to put the problem in context with some statistics. For an exit ramp to be completely compliant with the program standards, its exit number has to be posted in at least three different locations along the driver’s path: on a distance sign in before the exit, at the exit gore and at the beginning of the exit ramp. According to records dated May 1, 2008, there were 5,985 exits in the Cal-NExUS system. Only 19.5% (1,165) of those exits are in full compliance and 32% (1,913) exits are in minimum compliance. A full 57.1% (3,418) exits are in partial compliance, and the last 2,567 exits are not compliant with any aspect of the requirements whatsoever. As I have alluded to before, the levels of Cal-NexUS compliance varies widely from district to district within the state.

This sign is in partial compliance of the Cal-NExUS policies. It is on northbound I-405 at the Ventura Blvd exit in the San Fernando Valley. Only the Ventura Blvd sign has an exit number, and the middle sign indicating the next upcoming exit does not list an exit number as it should.

The efficiency of a wayfinding system is always measured by its consistency, and the exit numbering system for navigational purposes in California is lacking in such efficiency. I suggest that Iwasaki makes Caltrans look into cost-effective ways of making all 5,985+ exits in its system compliant with the standards set forth so that residents and visitors alike can navigate more easily. Hopefully a reliable numbering system can reduce wayfinding woes for people such as myself who only travel long distances on the freeway when we really must.

One issue that Iwasaki and Caltrans need to address along California’s roads is the legibility of signs and other wayfinding devices for the general public, including those with visual impairments, those over 65 years of age and those who are not familiar with the road names and signs but still need to easily recognize where they are to navigate.

Driving around Southern California, I have not seen that the state has adopted Clearview, a typeface system that was developed over the course of a decade by typographers, perceptual psychologists, human factors scientists and highway engineers. It was made to increase legibility and improve ease of recognition on road signs while reducing the consequences of that horrible glowing effect you see on reflective street signs everywhere.

Clearview is the only typeface approved by the Federal Highway Administration for highway signage other than the old standard FHWA typefaces developed back in the 1940s to work with almost all words are capitalized. Clearview is better both subjectively and objectively. Why, you ask? Below are the top three reasons:

Clearview on left is compared to FHWA Standard Highway Alphabet Series E on the right

1. It’s More Legible: According to the Transportation Research Board of the National Research Council, Clearview improves nighttime sign reading distance by up to 16% compared to the existing road sign typeface FHWA E-modified. This legibility enhancement translates into allowing drivers traveling at 45 M.P.H. an extra 80 feet of reading distance, which can mean a substantial 1.2 seconds of additional reading and reaction time while on the road.

2. It’s More Recognizable: Unlike other wayfinding fonts that use all capital letters, Clearview integrates upper- and lowercase letters to allow a viewer to read the footprint of a word. As summed up by the Arlene R. Gordon Research Institute, typographers agree that word shape is more distinctive with mixed upper- and lowercase than it is with all uppercase because all uppercase characters are the same height and have no ascenders (like the tall parts of d’s or b’s) and descenders (like the low parts of p’s and q’s), whereas lower case characters, which have both ascenders and descenders, can vary in both height and average position.

This variation makes full words more distinctive in shape and contours, so there is an increase in accuracy, viewing distance and reaction time when compared to all uppercase. Research shows that Clearview has a 14% increase in recognition when viewed by older drivers at night than the original freeway typeface FHWA Series D.

Clearview, at the bottom, exhibits the most legibility with halation.

 3. It’s Optimized Against Glare: Clearview’s 10 years of development optimized it to control overglow and underglow attributed to high brightness and reflective roadside sign materials. Clearview helps to maintain greater word pattern recognition for drivers with reduced contrast sensitivity as shown in the simulated example. This glow effect caused by reflecting materials is called halation or irradiation, and it becomes a problem if the stroke of the letterform becomes so bright and blown out that is begins to eat into the letter’s open spaces (called counters). The glowing, blobbing effect is cut down by the wider design of Clearview’s letterforms and their counters as well as the increased space between each letter.

Clearview has been in use across the U.S. since it was granted interim approval for national use on road signs in September 2004. It enhances legbility and accessibility for drivers of all sight abilities. With several different members in the Clearview font family, including positive contrast versions (white type on dark backgrounds) and negative contrast versions (black type on lighter backgrounds), the typeface could improve legibility and accessibility across California. It has been adapted for use on highways, city streets, warning and guidance signs, workzone signs, regulatory signs, and roadside listings of motorist services.

Positive and negative contrast variations of Clearview

With such a diverse population, a high number of tourists and travelers, and a growing older market, Caltrans should initiate a program and funding to replace old, hard-to-read signs with highly legible Clearview signs. Because Clearview is better while still being the same size as current signage fonts, it can improve wayfinding without forcing the state to spend millions on larger signs, as was feared back in 1994 when a major FHWA study recommended that standard signs increase letter height by 20% to accommodate viewing distance and reaction time requirements for older drivers. In addition, it can improve guide signs, and tons of various sign installations can be made more modular in design. This will reduce signage clutter, enhance wayfinding effectiveness, and improve the visual driving space. This is especially true for cities and states that are attempting to place more information on the roadscape to denote tourism-related activities, new regulations, and pedestrian safety protocol. These areas are already densely packed with assemblies of guide and regulatory panels, and Clearview could help clear the way.

Plus, Clearview is such a beautifully designed typeface, why not display it across the state?

Today I came across something significant, but I cannot decide if it surprises me or if I expected it all along. I thought I would share with you my findings, especially in light of what I discussed in my last post.

According to the Federal Highway Administration, approximately 4,000 lives are lost on California’s roadways annually. Nearly 54% of those fatalities occur on local roadways. With such a large and complex transportation that includes 347,000 lane miles of roadways and 36 million residents, there is a wide range of safety issues facing California. The state’s diversity and geography don’t help either.

Back in 2005, the (succinctly named) Safe, Accountable, Flexible, Efficient Transportation Equity Act – A Legacy for Users (SAFETEA-LU) required each state to develop and implement a Strategic Highway Safety Plan (SHSP). The SHSPs had to provide a framework for reducing highway fatalities and injuries on public roads by establishing statewide goals and emphasis areas. All SHSPs were developed by federal, state, local, and private sector safety stakeholders and based on behavioral and infrastructure-related strategies.

California’s SHSP was approved in 2006. Caltrans partnered with the California Office of Traffic Safety, the California Highway Patrol, and the California State Association of Counties in a 13-member committee to develop 16 Challenge Area teams. The teams included experts from the “Four Es” of safety: Engineering, Enforcement, Education and Emergency Medical Services. From there, Caltrans hosted Safety Summits in May 2008 to discuss implementation of the 152 SHSP actions. Representatives of state, city, and county agencies, private sector businesses, safety stakeholders, grass-roots organizations, and other key safety partners were all there.

And apparently none of them knew anything about environmental graphic design.

Each of the 16 Challenge Areas and corresponding emphasis areas identified by all of these experts included several mentions of increasing driver competency, developing educational and prevention programs, enhancing training and encouraging public transit. All of these to me seem like a lot of second-hand talk and not enough doing. What about the drivers who will not be impacted by prevention programs? What about visitors to the state? What about California’s current road systems? All of the 16 Challenge Areas had room for design solutions that would more directly address the problems, but none of them outline any. Behind the jump are the 16 areas with what they suggest and what I suggest. Don’t forget about design, Iwasaki!

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