Short answer: Rush-hour traffic usually no, non-rush-hour traffic often yes, based on a sample of speed estimates for Santa Monica Boulevard

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We don’t have the data to compare speeds on all streets in West Hollywood to all streets in nearby communities at all times. Instead, we’ll compare a sample of speed estimates for the city’s stretch of Santa Monica Boulevard to three nearby streets.

When we talk about traffic, we often focus on the morning and evening rush hours. However, West Hollywood isn’t a nine-to-five city and its traffic isn’t either. So we’ll look separately at rush-hour and non-rush-hour speeds.


Rush-hour versus non-rush-hour

Our prior report analyzed estimated driving times sampled over a few weeks last year. In that sample, driving across West Hollywood on Santa Monica Boulevard took an estimated 7 to 24 minutes. That means delays ranged from 0 to 17 minutes.

Yet, the same data source tells us that, at times, the trip can take up to 40 minutes. That’s a 33-minute delay. We know longer delays happen, but they didn’t happen in our limited sample, so we can’t say anything more about them.

In our sample, the slowest times were mostly during the rush hours, which we can see in the chart below. The end-to-end travel times look like a mountain range:

  • The AM and PM rushes stand out as the two big orange-colored peaks
  • The rush hours clearly had higher delays (orange) than most of the non-rush hours (yellow)
  • The non-rush hours still exhibited significant delays, represented in the chart by yellow hills

Note: Time of day runs from left to right. The day of week runs from front to back, starting with Sunday on the front edge. The height is the number of driving minutes. The heights are also color-coded, with yellow for 10 to 15 minutes, orange for 15 to 20 minutes, and red for more than 20 minutes. Sources: Google; our analysis.

Our earlier sample didn’t include data for the three comparison streets. So we took a fresh sample in the last few weeks. We gathered estimated driving times once an hour. We couldn’t directly compare driving times among the streets, because the streets are different lengths. Instead, we used end-to-end speed. We calculated it by dividing the total distance by the estimated driving time, which includes time spent at red lights.

The speed estimates for West Hollywood highlight the difference between rush hours and non-rush hours. In our sample, the fastest end-to-end speeds for West Hollywood were around 25 miles per hour and the slowest were under 10 miles per hour. About 95% of the times with the slowest speeds were during the rushes. Speeds in non-rush hours were higher, though not necessarily high. For example, 70% of the times that speeds were between 10 and 15 miles per hour were non-rush.

Note: Estimated speed driving from one end to the other during the sample period, excluding a holiday. Sources: Google; our analysis.


Rush-hour speeds compared to nearby streets

We used the sample data to compare speed estimates for four street segments:

  • Santa Monica Boulevard in West Hollywood
  • Santa Monica Boulevard in Beverly Hills
  • Santa Monica Boulevard in Hollywood
  • Olympic Boulevard running parallel to West Hollywood’s stretch of Santa Monica Boulevard

We chose Olympic as a proxy for broader east-west traffic flows that pass through communities in the middle.

We found that West Hollywood’s rush-hour traffic was neither the worst nor the best among the four. It was rarely the slowest in our sample: only 15% of the time during rush hours. That was similar to the situation on Olympic Boulevard (17%). Beverly Hills and Hollywood, on the other hand, had the slowest traffic 36% and 31% of the time, respectively.

Notes: (1) Half credit given if a segment was slowest in one direction but not the other. (2) We defined the rushes as 6:30 AM to 9:30 AM and 2:30 PM to 7:30 PM. Sources: Same as above.

West Hollywood wasn’t the fastest during rush-hour either. Among the four street segments, it had the fastest traffic only 16% of the time in our sample. Olympic was the winner, with faster rush-hour traffic 38% of the time.

We tried another version of these numbers that adjusted for possible inherent speed differences among the streets. The numbers changed a little, but the pattern was the same.

We know that our limited sample didn’t capture longer delays that can happen in West Hollywood. Of course, we may also have missed times with longer delays on the other three streets. We can assume the overall pattern would hold with more data, but we can’t prove it.


Non-rush-hour speeds compared to nearby streets

West Hollywood’s non-rush-hour traffic on Santa Monica Boulevard was usually the slowest of the four in our sample. It was the slowest 73% of the time. The Beverly Hills (8%), Hollywood (9%), and Olympic (10%) segments were rarely the slowest during non-rush hours.

Sources: Same as above.

Olympic was the fastest almost half the time. West Hollywood had the fastest non-rush-hour traffic only 3% of the time.

Again, we tried adjusting for possible inherent speed differences. The pattern was similar.


Non-rush-hour breakdown

West Hollywood’s slower non-rush-hour traffic on Santa Monica Boulevard wasn’t limited to one part of the day or week during our sample period. For example, we compared the estimated end-to-end speeds for West Hollywood and Beverly Hills. Weekday traffic was slower in West Hollywood, both in the middle of the day and at night. Westbound traffic was about 20% slower at noon and 11 PM.

On the weekend, westbound traffic was also about 20% slower at noon, according to the estimates. In fact, the graph of West Hollywood’s Saturday daytime traffic speeds looked a lot like a weekday.

Weekend nights were, of course, slower. Westbound traffic at 11 PM on the weekend was a third slower on average in West Hollywood than in Beverly Hills. The biggest difference was on Saturday night, followed by Friday night, then Sunday night.

Notes: (1) We excluded Friday from the weeknight estimate and included Sunday in the weekend-night number. (2) We tried adjusting for possible inherent speed differences between the two street segments. The resulting non-rush-hour speed gaps were smaller but still there. Sources: Same as above.

Revised to make clear that this report is based on estimates from a limited sample and that, even though we know longer delays happen, they weren’t captured in our sample.


http://wehobythenumbers.com/wp-content/uploads/2018/08/201808-traffic-slowest-nonrush.jpghttp://wehobythenumbers.com/wp-content/uploads/2018/08/201808-traffic-slowest-nonrush-300x300.jpgDavid WarrenPerformance (effectiveness)Transportationbeverly hills,hollywood,los angeles,traffic
Short answer: Rush-hour traffic usually no, non-rush-hour traffic often yes, based on a sample of speed estimates for Santa Monica Boulevard| We don't have the data to compare speeds on all streets in West Hollywood to all streets in nearby communities at all times. Instead, we'll compare a sample...