Degrading overall Downtown Safety for the sake of a few

(A Message to the citizens of Los Alamos, NM)   
 

There have been lots of claims about how safe roundabouts are and how much we need bike lanes on Trinity. Most of the blather for the change is passionate rhetoric from bicyclists and folks who apparently love circles. Many, not in these groups, have been voicing opposition. The county council voted 5-2 to bow to the desires of the few.  

Below I have put together some data (from the LA traffic engineer, police department and CDM study) in an attempt to see what is going to happen to the entire town (not just Trinity) with regard to traffic redistribution and safety, if Trinity is changed from 4 to 2 lanes.

This daily average vehicular data is from the LA Traffic Engineer (Zimmerman) plus CDM ( 9/15/2010 )

Notes based on these data:

• The move of the county complex to east gate lessened the load west of the airport (less density in town).  

• The east side traffic load in 2010 was 63% onto Trinity (main route thru town and into business district thru its south doors), 35% onto Central (main entrance to downtown) and 3% onto Canyon (east entrance to downtown via its north doors, residential areas and an alternate, twisty, by-pass of the business section to the other side of town).  

• As CDM Trinity data is significantly higher than the CDM in/outflow of 502, there is a significant Trinity-DP load.  This load is not likely to change, so any decrease in Trinity traffic will have to be diverted before this intersection.

This is Traffic Incident data for the last 5 years from the LA Police Department (Berg/Torpy)

Notes based on these data:

• The data is for the past 5 years, except for the fatality data which covers a longer period as there are fortunately few. Note that both major routes through town have comparable numbers and thus does not indicate that one is more dangerous than the other. Central-Canyon total accidents could be slightly lower if accidents for the Aquatic Center to 502 are included in the data supplied to me.

• However, comparing the accidents/load of 2-lane Central-Canyon (with 15-25-35mph segments, bike lanes on the west end, and numerous cross-walks – signaled and not) with that of 4-lane Trinity (with 35mph, turning bays, no bike lanes, and cross-walks at major intersections) shows that the 2-lane route through town has had twice the accident/load of the 4-lane route.

• Both routes have a death associated with them. The deaths on each route have come from pedestrians hit crossing the road. That on Canyon occurred just south of the Aquatic Center in a marked cross-walk. The pedestrian hit on Trinity was crossing mid-block in the Ashley Pond area. If crossing is to be permitted between intersections on Trinity, walk-don’t walk lights/traffic stopping signals should be installed (note that deaths have occurred where there have been no such signals).

• While roundabouts are touted to eliminate head-on collisions, this as an especially dangerous condition for the current 4-lane, 35mph Trinity configuration with turning bays. Island separation of opposing lanes is probably more significant over long, max velocity stretches than are roundabouts at intersections.

 What will happen if 4 lane-Trinity to converted to 2 lanes, regardless of flow control?

1.      Going from 4 lanes to 2 will not decrease traffic–related incidents. Indeed a higher density of vehicles per linear foot of road should lead to more incidents, not fewer, based on actual, reported, Los Alamos data.

2.      Assuming Trinity can handle 2/3rds of its current load (can a 2-lane road possibly handle what a 4-lane one does?), the remaining 1/3^rd will have to go to Central and Canyon. Large increases in traffic density on these streets will dramatically increase their traffic-related incidents.

If Trinity can carry 80% of its current load and Central carries most of rest

 Ø            Just a 20-33% decrease in Trinity load will dramatically increase traffic on the two remaining through-downtown roads!

Ø            The new county headquarters on Central with increase traffic unassociated with the Trinity situation. Thus, with the County building on it, Central is NOT likely to handle much of the Trinity excess!

Ø            Canyon is the only other route. It is a residential street for much of its eastern length. A 140-500% (2.4x-6x) increase in its traffic will put children, pedestrians, and vehicles at enormously greater risks.

Ø            A 30-50% increase in traffic at Canyon-Diamond will also create substantial hazards, especially with its heavy pedestrian school activity as the crosswalk favored by those who do not wish to use the pedestrian overpass. Note that the hit bicyclists were where Diamond intersects Canyon and Trinity.

Thus, while a 4-to-2 lane change will decrease the vehicle load on Trinity, doing so will dramatically increase the loads elsewhere in the town and lead to dramatically greater risks for all citizens and visitors throughout the town without a concomitant decrease in incidents on Trinity! Indeed, comparative police incident data indicate that not even Trinity will be safer with just 2 lanes, in spite of those vehemently voicing that it will be.

1.      They are placating <2% of the population at the expense of the other 98%. This is being done by decreasing overall safety downtown so a few (<100?), serious bicyclists can have biking turnpikes to and from the hospital and airport. Considering that the Diamond bike lanes get sparse use (mostly to/from north of Trinity and the south side of LA Canyon – lab and Jemez routes), dedicated lanes on Trinity are not likely to get much use at all. Frankly, clamoring bicyclists should be encouraged to stroll leisurely through downtown and visit some of the local businesses. Aren’t they promoting that, by giving them turnpike bike lanes and throttling traffic on Trinity, more “drop-in” business will result for downtown?

2.      Citizens are at the whims of those enamored with roundabouts and who apparently have significant control over traffic recommendations to our council representatives. Apparently they think that Los Alamos is anemic in the crop-circle department and thus needs some in spite of public opinion to the contrary (re: Diamond and WR Route 4). The Diamond-San Ildefonso roundabout (DSI) is often cited as proof that roundabouts are elixir solutions to all traffic problems, when, in fact, almost none of the features that make DSI work (esp., primary input and output from 4-lane Diamond) will be present on Trinity. Indeed, 40% of all the vehicles that approach the DSI  intersection NEVER actually enter the roundabout portion, but by-pass it so as not to interfere with the other major flow that actually does go into the roundabout! Nor does DSI have bike lanes. It also has little vehicular cross traffic and little pedestrian traffic. Thus, DSI is not a good model for Trinity. In fact, DSI would probably not even be satisfactory to those who espouse it, if all of the traffic actually entered the roundabout!  

3.      A few citizens and committees are attempting to persuade the rest of us that the majority of the public actually favors 2-lanes with abundant roundabouts for Trinity. This comes, for example, from reports that small (~100 participants) “public forums” favor the “2-lane with roundabouts approach” by 58% and that this must be what the majority of citizens favor. These small groups and advisory committees are stuffed with special interest people (that is how small vocal factions get a voice in the democratic process!). Such bias, however, does NOT provide a statistical representation of the whole community. Statisticians would LOL at the implication. Too many of the assemblages in this issue are dominated by those who are not satisfied with already having bike lanes on 1/2 of the roads headed east into downtown from Diamond, but greedily want Trinity furnished likewise.  

The overall safety of its citizens should be of utmost concern to the county council.  However, five of the councilors moved to have the Trinity revamping reduce its 4 lanes to 2 with roundabouts. They did so, either knowing that they are putting the vast majority of citizens AND visitors in greater peril for the benefit of a few or in ignorance by not having requested an analysis of what would happen everywhere, not just on Trinity. If they made their decision by being told that a 4-to-2 lane decrease would not reduce the vehicle flow level on Trinity and would significantly improve safety, they are a gullible bunch, indeed. Even with considerable, voiced opposition to this maneuver, recently and in the past, these five county representatives have indicated, for the record, that they are more interested in serving small special interests than they are in serving the whole community. Such behavior is imprudent. Citizens are now left to pay for and endure a project design that will not only inconvenience them, but put them at greater peril. Is this what we elected our councilors to do?

Joel M Williams
51 Zuni
Los Alamos , NM
662-9505
jmw-mcw@swcp.com