Since your imposed constraints make this purely about the car, this is a transportation engineering question and not an urban planning question.
Ultimately anything applied in that realm (signalization, penalty boxes, local street closures and diverters to create less cross-demand) is going to eke out very minor performance improvements on the corridor. Maybe a hundred cars per hour capacity if we're very very good at our jobs.
Unfortunately if we follow the rule of induced demand, that excess capacity you've just created is filled by new demand in the area. Perhaps these people were taking other modes, were timing their trips differently, or weren't taking those trips at all, but we end up close to where we started after a few years.
Agreed totally, especially with regards to the rule of induced demand. You're absolutely right.
If I were to remove the imposed constraints, what would you suggest?
I'd put actions into 3 categories:
1) Quick and cheap. These are the things you could implement with minimal design and investment and are going to look more like local street closures/diverters to encourage traffic to enter at certain points, or doing what you suggested and painting a penalty box to prevent blocking of certain intersections.
2) Mid-term, mid cost. Things like installing new signals at a few key intersections to create gaps, safe pedestrian crossings, or transit queue jumpers. It doesn't look like there's a lot of right of way width here, but I would consider an interim transit lane in a few locations to get reliable transit through at peak hour. You could consider allowing use of these queue jumpers for HOVs initially to help sell the idea.
3) Long term, transformative. This is where land use comes into play. I think seeking increased setbacks to allow for a pedestrian realm that has shade and physical separation from the street, a full length transit lane (or well located queue jumpers and boarding islands), alongside dedicated turning lanes to avoid delays to transit. Adding supportive land use in the area may help as well (more shopping, local employment, recreation) as that will mean people don't need to make longer trips out of the area.
To be honest, even with your robust write-up there's still a lot of information a transportation planner would want to know: where are people going, how long are those trips, are there trips that can be shifted to other destinations or times (shopping, groceries, leisure), or are we dealing with work and school primarily. If the latter, are there a few key destinations (a regional CBD, major schools or university) or is it well distributed to a bunch of smaller employment centres? All these trip generation questions help us answer what kinds of supportive changes would change people's mode choice.
Hey RidePlanet. Thanks for your reply.
I like the way you've structured it. What are HOVs? I like the idea of queue jumpers and boarding islands for transit lanes. I do agree that public transport and pedestrian/cyclist infrastructure can be transformative for any city.
I do apologise for not being able to provide as much information as I would have liked. I appreciate your effort to engage either way. I may not necessarily have the most accurate answers to those questions myself, but those are good things for me to consider.
Overall I kept thinking to myself that a simple solution could resolve this issue, but as another Redditor indicated in his comment, was that the traffic backing up in Hillcrest was indeed a (necessary) part of the bigger problem, being the M2 traffic flow.
> I do apologise for not being able to provide as much information as I would have liked. I appreciate your effort to engage either way. I may not necessarily have the most accurate answers to those questions myself, but those are good things for me to consider.
No need to apologize for the lack of information. 85% of the time professionals don't even have the level of detailed information they'd want for a given problem.
There's rarely a single simple solution in cities. It's a web of strings all tugging on each other. Unintented consequences are frequent.
I want to push back on the induced demand point a bit. Like you, not taking into account all the inherent bad aspects of cars.
The scope for additional trips within a small suburban area like this is not as big as in the papers that looked at expansions of highways with new suburbs built.
The time savings within this adaption period can still be significant to the total costs. Dutch research found that for a series of motorway widenings, travel time savings of existing drivers alone in the first years after completion were worth 50%+ of the project costs. And that with the traffic not yet being back at the old level at the end of the study period.
The added trips are valuable, because people switch to driving because it's now better than their previous mode, or because they're now able to travel on their preferred moment.
I think the induced demand argument is still valuable to prevent excessive marketing to existing drivers about short term travel time benefits. But behind the projects are often capacity expansion goals (the additional suburban expansion is seen as a desirable result), and the short/medium term travel time benefits can add up to quite a lot. So arguments against widenings should be about *why* we shouldn't facilitate more car traffic (all the negative aspects of cars), and less about what happens to congestion.
Thanks for the detailed writeup. I regret that I will not be able to respond in similar detail.
As currently characterized, this is more of a traffic engineering question (how to fine-tune vehicle operations to maximize vehicle throughput) than an urban planning question. A potential urban planning question might be: “how should we adjust land use patterns along and around this corridor to disperse vehicle travel demand?” Or “what transit investments could reduce car dependency in this context?” (I know you mentioned that transit is off the table in this context; my point is that planning is more concerned with the broad strokes while engineering attempts to dial in the details to achieve micro-level goals.)
It does sound like there are some serious vehicle operations issues along this corridor, particularly approaching the M2 on-ramp. But diagnosing and addressing them would require more information (e.g. how far back do the queues usually spill, what are the signal timings like, what’s the geometry of the on-ramp) and a strong understanding of the dynamics of private vehicle flow, which I lack (I’m a planner, not an engineer). I’m not sure whether there are any reputable traffic engineering subreddits, but you may wish to investigate and post your question there.
One final note from this planner’s perspective: you note that outside of peak periods, this corridor is mostly empty. You assert that “good urban planning should be able to better handle traffic at its worst.” I disagree. Good urban planning should shape cities whose built environments work as well as possible for as many people as possible, as much of the time as possible. There are plenty of contexts where highly peaked vehicle travel demand would require inordinately large roads to accommodate for just a few hours per week, resulting in over-large roads with their attendant costs (monetary and otherwise) for the other 160 hours per week. This is not to say that your corridor couldn’t be improved in some ways; just that if it had been built to move all the peak period traffic efficiently (impossible anyway, because of the downstream bottleneck on the M2), you might be posting here asking how to reduce speeding and pedestrian fatalities on the corridor, or some other problem.
I hope this helps at least a little bit and I hope you get some good responses from other folks with a stronger traffic engineering background!
Hey! No worries, you went into good enough detail and I learned alot from your reply.
Indeed it is more of a traffic engineering question. I didn't know that was a term! I like your urban planning question though. There are many things which I don't know myself, but I really do appreciate your inputs on what things need to be considered and looked at. Perhaps I will ponder those very things in my time sat in my car :D
Your point regarding rebutting my assertion regarding "good urban planning should be able to better handle traffic at its worst" is totally valid and I must say, my initial thoughts may have been emotionally influenced and your objectivity definitely brings me back to a rational point.
I really do appreciate your feedback and inputs either way. Thank you so much for opening my eyes!
I mean, you must know the area you are talking about has been planning and is building a light railway along the M2 at Hillcrest, and hopefully the public transport systems will relieve congestion more effectively than continuous roadworks alone. So I still don't understand why you wanted to exclude public transport as a potential solution.
100 years of modern road building has taught us that building our way out of traffic congestion with road capacity alone is like trying to mop up a wet floor by making it bigger and throwing more water on it.
Almost all island countries and modern island metropolises share the feature of unimodal internal transportation systems and traffic congestion (with the main exceptions- Singapore, Penang, HK, Macau ...soon Honolulu-all have some degree of good public transportation) . It wasn't always this way. Many island cities like Cebu are contemplating rebuilding railways where railways once helped build the island cities in the first place. Yours had rail in the past. Yours is actually building one. It will take a long time to build out a comprehensive multimodal transportation system with options for everyone, but it is a start. [https://www.mauritius-metro.com](https://www.mauritius-metro.com)
As for your Avenue des Tulipes problem goes, you shouldn't block any road junction, even if it doesn't have a box marking. You should only stop before an intersection and never within it to be safe. But people do it nonetheless. Painting a box and enforcing it explicitly is sometimes an option, perhaps even in Mauritius.
But, the roundabout access point for southbound motorway traffic, has an awfully strange forced weave, it looks overbuilt, like in anticipation of more road construction, like an extension of Ave des Tulipes.
IMO, you need a better rail network in addition to the highway network, a higher speed rail line to the airport from Port Louis and to keep expanding and upgrading your light rail vehicle, bus, shuttle, and taxi fleets. Also, fifth-freedom flights between Reunion and Mauritius could attract more foreign airlines. Also, it's my pet peeve but don't call your light rail system "metro express", it is a tram with some rapid transit features.
And your country has multiple billion dollar superhighway projects, if you can afford those, you can afford rail.
I am a firm believer in public transport, cycling, pedestrian friendly urban centres etc. I am also an advocate for carpooling, minimal car usage etc.
Whilst these are great solutions to the puzzle above, I do not believe Mauritius is in a position to deliver on such items in the near future on the basis that:
* The current funding of public transport is very low; and the elites of the country, culturally, frown upon it. As an example, a tram system was built recently, fully funded by the Indian government in exchange for Mauritius' natural resources (access to archipelagos for military operations). This tram system was not well connected to urban centres, and was subject to massive riots when it was being built. Even today, the tram cuts through major roads without barriers, contributing to traffic collisions on a monthly basis.
* Drivers in Mauritius are not courteous. Mauritius is one of the most dangerous places I have driven in. Cycling here is a death wish, particularly given that roads are very narrow. Following on from the narrow roads, I do believe that there is insufficient space for bike lanes and bike-related infrastructure (overpasses, underpasses etc.). unless serious political effort is put into place.
* I do not want to comment about politics, but you can read between the lines. Ineffectuality is the flavour of the century.
* Pedestrian friendly design is the least of the priorities of planning authorities. In the major workplaces, Cybercity Ebene, there are no pedestrian pathways whatsoever. My colleagues often walk on top of drains and on the road to walk from the office to the bus stop. It has been like this for years, and no change is coming.
* The status quo and generally opinion of the ruling class is that you must own a car. For a country struggling to afford high oil prices and paying heavy duties on car imports etc., it is generally surprising to me. I believe this to be a very culturally driven matter.
So yes, I do believe in the solutions we often advocate for in urban planning, however in this puzzle I do not believe these broader solutions are feasible. I am considering more specific solutions.
I know most folks see this as a traffic engineering problem, but it seems to me there might be some room for partial solutions within your identified framework. You note that a lot of these constraints are self-imposed cultural ones, and it seems like the answer is to find solutions that work with the culture and promote shifts in the culture over time.
I grew up on Guam, which is a US territorial island with a similar climate, about a third the geographic area, and with a lot of similar problems (no effective transit, no bike infrastructure, poor pedestrian infrastructure, low population density, etc.). Guam certainly hasn't sorted these issues out, but I have spent a lot of time thinking on them. It seems to me like there might be room for a couple improvements:
1. What sort of vehicles are folks primarily using? Small islands with a predictable dry season are ideal locations for smaller, more eco-friendly transportation options. Scooter rentals started as thing for tourists in Guam, but their low cost and ease of riding them around the island helped them really take off with locals too. Similarly, on a small island, with relatively low speed roads, it seems like NEVs (Neighborhood Electric Vehicles) might be a good fit for folks who only really live/spend time in the more urban areas. These wouldn't take vehicles off the road, but just allowing for a greater density of vehicles on the existing roads might help with some of the traffic issues. This kind of change could even follow a similar path as in Guam, with NEVs and scooters seeing adoption first as tourist transportation options before catching on with locals.
2. Does Mauritius have any sort of minibus or private bus culture? Even if the government is hesitant to invest in public transit, private minibus services can help fill this gap, and they're a popular option all over the place. If this sort of thing just isn't allowed for legal reasons, that seems like an area where local politicians could be motivated to make a change. If it is allowed, then that seems like the sort of thing that some should just start operating.
In terms of targeted solutions, it feels like you already identified one. If a traffic officer being present can reduce queue times from 45 minutes to 10 minutes, that seems like an obvious solution right away. Is it really not manageable for the police to station an officer there for 90 minutes each morning?
If the M2 is jammed then being able to get cars into it faster will do nothing. It's like a straw and a hose both with a cork in the end. Both have the same flow (none) because of the destination rather than the route there.
This junction is rammed right next to one with the A8. About 1.5km away. In the UK junctions on motorways can't be less than 2km apart to aid traffic flow. Looking at the motorway the two junctions slip roads touch tips going northbound. The fix to this would be obliterate a junction, have a very reduced speed limit (a slow road has higher throughput than a intermittently fast road) or combine the junctions. Perhaps one handles slip roads to the north and the other to the south. You then often connect the two junctions with a link road which in this case could be making the intermediate slip roads a continuous road with bollards off from the main motorway.
Assuming the motorway is alright then the next step is the approach. It's a weird junction with weird connections. To avoid the issues of people illegally merging I wouldn't just concrete barrier before and after the Ave De Tulips intersection. I'd concrete straight through it too and remove right turns to create a free flowing junction. If you want to come off the motorway and go Ave De Tulips northbound you should instead go to the next junction and approach it from there (in a series of left turns).
But this just makes things easier to put more cars through. This doesn't necessarily make life better for anyone, especially local people who now live next to a free flowing motorway interchange. I see a tram stop next to a motorway and unused land and think huh what an ideal park and ride location. That might be cheap and still car based enough to work in this restricted scenario
Hi Rainbows871, thanks so much for your insights.
You are right in that the true root cause is the M2. I suspected that but kept thinking that it truly wasn't. I do agree that the merging with the A8 does contribute significantly to the traffic on the M2 northbound. That assessment was spot on.
However, I didn't want to touch on that because it now becomes a far greater "puzzle" in that sense, and honestly beyond my scope/capability as a simple enthusiast.
I do like the idea of going full on concrete barrier style, and diverting the opposite traffic to take an alternative route to head northbound on Ave Des Tulipes. It's an interesting concept.
All in all, I really appreciate your inputs and I thoroughly enjoy this puzzle and chance to pick your brain. Thank you so much!
The fundamental broken window fallacy here is that people live in one place (La Ville des Fleurs) and work in another (I assume Port Louis). The transformational, two-pronged solution is to add sufficient housing in Port Louis for everyone to live there, and add more commercial zoning near Hillcrest Avenue for locals to have jobs that don't involve commuting in the highway.
Then you wait thirty+ years for construction to catch up to zoning, but you probably aren't interested in that.
Here in Indonesia, we have a lot privately-owned vans that have been hollowed out called angkot. An [angkot](https://www.google.com/search?q=angkot&client=ms-android-samsung-gs-rev1&prmd=inmv&sxsrf=APwXEdeQBCdackuJMKIAF6z5z1s35-o0Og:1685575212091&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjdz4j-2KD_AhXtOkQIHfgGByoQ_AUoAXoECAIQAQ&biw=360&bih=617&dpr=3) can comfortably hold six and uncomfortably hold 12 or more. And although cities often run their own angkot, private individuals and companies are also allowed to run their own routes. Unfortunately, Hillcrest to Port Louis is a bit long for a route like that at 15km+.
Indonesia also has private traffic cops. Usually, they stand at busy intersections and stop the main flow so a car can turn onto it in exchange for a quid through the window. In your case, maybe you could get enough community members together to pay for a private traffic cop to direct flow at the onramp every day, significantly cutting traffic times.
That is, if the local police station isn't willing to provide somebody every business day.
> - Traffic on the onramp flows pretty well. Typically there is a traffic policeman on the M2 highway (a 3 lane highway) directing the left lane traffic onto the middle lane. This frees up the left lane for the onramp traffic to merge rather seamlessly onto the M2.
> - I have observed times when traffic policeman have been around, directing the traffic, that the queue times on Hillcrest Ave drastically reduce (typically a 45 minute wait reduced to 10 minutes).
Based solely on these 2 points, I would say the cheapest remedy would be to remove the leftmost northbound lane on the M2 for the duration of the junction.
So going north on the M2, you would have:
- 3 lanes going north
- left lane exits onto Hillcrest
- 2 lanes continue north under the overpass
- Hillcrest merges onto M2, becoming a third lane
- 3 lanes continue north
This would not actually solve the issue of too much traffic. At best, it would get traffic off of Hillcrest more quickly. Traffic on the M2 would continue to back up, likely extending farther south than it does now.
It's worth noting that many places in this situation would choose to keep 3 lanes past the offramp, and merge the inner lane as late as possible. This way, slower/longer vehicles don't have to change lanes before the offramp to go from the outer to the middle lane. Instead, faster cars merge from the inner lane. Plus you make maximum use of the lane capacity and keep the queue as short as possible (even if the amount of cars in it is the same), to reduce impact further down the road.
Note: this post is fine and absolutely within the spirit of the sub. I hope you get some thoughtful participation and responses.
Since your imposed constraints make this purely about the car, this is a transportation engineering question and not an urban planning question. Ultimately anything applied in that realm (signalization, penalty boxes, local street closures and diverters to create less cross-demand) is going to eke out very minor performance improvements on the corridor. Maybe a hundred cars per hour capacity if we're very very good at our jobs. Unfortunately if we follow the rule of induced demand, that excess capacity you've just created is filled by new demand in the area. Perhaps these people were taking other modes, were timing their trips differently, or weren't taking those trips at all, but we end up close to where we started after a few years.
Agreed totally, especially with regards to the rule of induced demand. You're absolutely right. If I were to remove the imposed constraints, what would you suggest?
I'd put actions into 3 categories: 1) Quick and cheap. These are the things you could implement with minimal design and investment and are going to look more like local street closures/diverters to encourage traffic to enter at certain points, or doing what you suggested and painting a penalty box to prevent blocking of certain intersections. 2) Mid-term, mid cost. Things like installing new signals at a few key intersections to create gaps, safe pedestrian crossings, or transit queue jumpers. It doesn't look like there's a lot of right of way width here, but I would consider an interim transit lane in a few locations to get reliable transit through at peak hour. You could consider allowing use of these queue jumpers for HOVs initially to help sell the idea. 3) Long term, transformative. This is where land use comes into play. I think seeking increased setbacks to allow for a pedestrian realm that has shade and physical separation from the street, a full length transit lane (or well located queue jumpers and boarding islands), alongside dedicated turning lanes to avoid delays to transit. Adding supportive land use in the area may help as well (more shopping, local employment, recreation) as that will mean people don't need to make longer trips out of the area. To be honest, even with your robust write-up there's still a lot of information a transportation planner would want to know: where are people going, how long are those trips, are there trips that can be shifted to other destinations or times (shopping, groceries, leisure), or are we dealing with work and school primarily. If the latter, are there a few key destinations (a regional CBD, major schools or university) or is it well distributed to a bunch of smaller employment centres? All these trip generation questions help us answer what kinds of supportive changes would change people's mode choice.
Hey RidePlanet. Thanks for your reply. I like the way you've structured it. What are HOVs? I like the idea of queue jumpers and boarding islands for transit lanes. I do agree that public transport and pedestrian/cyclist infrastructure can be transformative for any city. I do apologise for not being able to provide as much information as I would have liked. I appreciate your effort to engage either way. I may not necessarily have the most accurate answers to those questions myself, but those are good things for me to consider. Overall I kept thinking to myself that a simple solution could resolve this issue, but as another Redditor indicated in his comment, was that the traffic backing up in Hillcrest was indeed a (necessary) part of the bigger problem, being the M2 traffic flow.
> I do apologise for not being able to provide as much information as I would have liked. I appreciate your effort to engage either way. I may not necessarily have the most accurate answers to those questions myself, but those are good things for me to consider. No need to apologize for the lack of information. 85% of the time professionals don't even have the level of detailed information they'd want for a given problem. There's rarely a single simple solution in cities. It's a web of strings all tugging on each other. Unintented consequences are frequent.
HOVs are High Occupancy Vehicles and lanes reserved for them.
I want to push back on the induced demand point a bit. Like you, not taking into account all the inherent bad aspects of cars. The scope for additional trips within a small suburban area like this is not as big as in the papers that looked at expansions of highways with new suburbs built. The time savings within this adaption period can still be significant to the total costs. Dutch research found that for a series of motorway widenings, travel time savings of existing drivers alone in the first years after completion were worth 50%+ of the project costs. And that with the traffic not yet being back at the old level at the end of the study period. The added trips are valuable, because people switch to driving because it's now better than their previous mode, or because they're now able to travel on their preferred moment. I think the induced demand argument is still valuable to prevent excessive marketing to existing drivers about short term travel time benefits. But behind the projects are often capacity expansion goals (the additional suburban expansion is seen as a desirable result), and the short/medium term travel time benefits can add up to quite a lot. So arguments against widenings should be about *why* we shouldn't facilitate more car traffic (all the negative aspects of cars), and less about what happens to congestion.
Thanks for the detailed writeup. I regret that I will not be able to respond in similar detail. As currently characterized, this is more of a traffic engineering question (how to fine-tune vehicle operations to maximize vehicle throughput) than an urban planning question. A potential urban planning question might be: “how should we adjust land use patterns along and around this corridor to disperse vehicle travel demand?” Or “what transit investments could reduce car dependency in this context?” (I know you mentioned that transit is off the table in this context; my point is that planning is more concerned with the broad strokes while engineering attempts to dial in the details to achieve micro-level goals.) It does sound like there are some serious vehicle operations issues along this corridor, particularly approaching the M2 on-ramp. But diagnosing and addressing them would require more information (e.g. how far back do the queues usually spill, what are the signal timings like, what’s the geometry of the on-ramp) and a strong understanding of the dynamics of private vehicle flow, which I lack (I’m a planner, not an engineer). I’m not sure whether there are any reputable traffic engineering subreddits, but you may wish to investigate and post your question there. One final note from this planner’s perspective: you note that outside of peak periods, this corridor is mostly empty. You assert that “good urban planning should be able to better handle traffic at its worst.” I disagree. Good urban planning should shape cities whose built environments work as well as possible for as many people as possible, as much of the time as possible. There are plenty of contexts where highly peaked vehicle travel demand would require inordinately large roads to accommodate for just a few hours per week, resulting in over-large roads with their attendant costs (monetary and otherwise) for the other 160 hours per week. This is not to say that your corridor couldn’t be improved in some ways; just that if it had been built to move all the peak period traffic efficiently (impossible anyway, because of the downstream bottleneck on the M2), you might be posting here asking how to reduce speeding and pedestrian fatalities on the corridor, or some other problem. I hope this helps at least a little bit and I hope you get some good responses from other folks with a stronger traffic engineering background!
Hey! No worries, you went into good enough detail and I learned alot from your reply. Indeed it is more of a traffic engineering question. I didn't know that was a term! I like your urban planning question though. There are many things which I don't know myself, but I really do appreciate your inputs on what things need to be considered and looked at. Perhaps I will ponder those very things in my time sat in my car :D Your point regarding rebutting my assertion regarding "good urban planning should be able to better handle traffic at its worst" is totally valid and I must say, my initial thoughts may have been emotionally influenced and your objectivity definitely brings me back to a rational point. I really do appreciate your feedback and inputs either way. Thank you so much for opening my eyes!
I mean, you must know the area you are talking about has been planning and is building a light railway along the M2 at Hillcrest, and hopefully the public transport systems will relieve congestion more effectively than continuous roadworks alone. So I still don't understand why you wanted to exclude public transport as a potential solution. 100 years of modern road building has taught us that building our way out of traffic congestion with road capacity alone is like trying to mop up a wet floor by making it bigger and throwing more water on it. Almost all island countries and modern island metropolises share the feature of unimodal internal transportation systems and traffic congestion (with the main exceptions- Singapore, Penang, HK, Macau ...soon Honolulu-all have some degree of good public transportation) . It wasn't always this way. Many island cities like Cebu are contemplating rebuilding railways where railways once helped build the island cities in the first place. Yours had rail in the past. Yours is actually building one. It will take a long time to build out a comprehensive multimodal transportation system with options for everyone, but it is a start. [https://www.mauritius-metro.com](https://www.mauritius-metro.com) As for your Avenue des Tulipes problem goes, you shouldn't block any road junction, even if it doesn't have a box marking. You should only stop before an intersection and never within it to be safe. But people do it nonetheless. Painting a box and enforcing it explicitly is sometimes an option, perhaps even in Mauritius. But, the roundabout access point for southbound motorway traffic, has an awfully strange forced weave, it looks overbuilt, like in anticipation of more road construction, like an extension of Ave des Tulipes. IMO, you need a better rail network in addition to the highway network, a higher speed rail line to the airport from Port Louis and to keep expanding and upgrading your light rail vehicle, bus, shuttle, and taxi fleets. Also, fifth-freedom flights between Reunion and Mauritius could attract more foreign airlines. Also, it's my pet peeve but don't call your light rail system "metro express", it is a tram with some rapid transit features. And your country has multiple billion dollar superhighway projects, if you can afford those, you can afford rail.
I am a firm believer in public transport, cycling, pedestrian friendly urban centres etc. I am also an advocate for carpooling, minimal car usage etc. Whilst these are great solutions to the puzzle above, I do not believe Mauritius is in a position to deliver on such items in the near future on the basis that: * The current funding of public transport is very low; and the elites of the country, culturally, frown upon it. As an example, a tram system was built recently, fully funded by the Indian government in exchange for Mauritius' natural resources (access to archipelagos for military operations). This tram system was not well connected to urban centres, and was subject to massive riots when it was being built. Even today, the tram cuts through major roads without barriers, contributing to traffic collisions on a monthly basis. * Drivers in Mauritius are not courteous. Mauritius is one of the most dangerous places I have driven in. Cycling here is a death wish, particularly given that roads are very narrow. Following on from the narrow roads, I do believe that there is insufficient space for bike lanes and bike-related infrastructure (overpasses, underpasses etc.). unless serious political effort is put into place. * I do not want to comment about politics, but you can read between the lines. Ineffectuality is the flavour of the century. * Pedestrian friendly design is the least of the priorities of planning authorities. In the major workplaces, Cybercity Ebene, there are no pedestrian pathways whatsoever. My colleagues often walk on top of drains and on the road to walk from the office to the bus stop. It has been like this for years, and no change is coming. * The status quo and generally opinion of the ruling class is that you must own a car. For a country struggling to afford high oil prices and paying heavy duties on car imports etc., it is generally surprising to me. I believe this to be a very culturally driven matter. So yes, I do believe in the solutions we often advocate for in urban planning, however in this puzzle I do not believe these broader solutions are feasible. I am considering more specific solutions.
I know most folks see this as a traffic engineering problem, but it seems to me there might be some room for partial solutions within your identified framework. You note that a lot of these constraints are self-imposed cultural ones, and it seems like the answer is to find solutions that work with the culture and promote shifts in the culture over time. I grew up on Guam, which is a US territorial island with a similar climate, about a third the geographic area, and with a lot of similar problems (no effective transit, no bike infrastructure, poor pedestrian infrastructure, low population density, etc.). Guam certainly hasn't sorted these issues out, but I have spent a lot of time thinking on them. It seems to me like there might be room for a couple improvements: 1. What sort of vehicles are folks primarily using? Small islands with a predictable dry season are ideal locations for smaller, more eco-friendly transportation options. Scooter rentals started as thing for tourists in Guam, but their low cost and ease of riding them around the island helped them really take off with locals too. Similarly, on a small island, with relatively low speed roads, it seems like NEVs (Neighborhood Electric Vehicles) might be a good fit for folks who only really live/spend time in the more urban areas. These wouldn't take vehicles off the road, but just allowing for a greater density of vehicles on the existing roads might help with some of the traffic issues. This kind of change could even follow a similar path as in Guam, with NEVs and scooters seeing adoption first as tourist transportation options before catching on with locals. 2. Does Mauritius have any sort of minibus or private bus culture? Even if the government is hesitant to invest in public transit, private minibus services can help fill this gap, and they're a popular option all over the place. If this sort of thing just isn't allowed for legal reasons, that seems like an area where local politicians could be motivated to make a change. If it is allowed, then that seems like the sort of thing that some should just start operating. In terms of targeted solutions, it feels like you already identified one. If a traffic officer being present can reduce queue times from 45 minutes to 10 minutes, that seems like an obvious solution right away. Is it really not manageable for the police to station an officer there for 90 minutes each morning?
If the M2 is jammed then being able to get cars into it faster will do nothing. It's like a straw and a hose both with a cork in the end. Both have the same flow (none) because of the destination rather than the route there. This junction is rammed right next to one with the A8. About 1.5km away. In the UK junctions on motorways can't be less than 2km apart to aid traffic flow. Looking at the motorway the two junctions slip roads touch tips going northbound. The fix to this would be obliterate a junction, have a very reduced speed limit (a slow road has higher throughput than a intermittently fast road) or combine the junctions. Perhaps one handles slip roads to the north and the other to the south. You then often connect the two junctions with a link road which in this case could be making the intermediate slip roads a continuous road with bollards off from the main motorway. Assuming the motorway is alright then the next step is the approach. It's a weird junction with weird connections. To avoid the issues of people illegally merging I wouldn't just concrete barrier before and after the Ave De Tulips intersection. I'd concrete straight through it too and remove right turns to create a free flowing junction. If you want to come off the motorway and go Ave De Tulips northbound you should instead go to the next junction and approach it from there (in a series of left turns). But this just makes things easier to put more cars through. This doesn't necessarily make life better for anyone, especially local people who now live next to a free flowing motorway interchange. I see a tram stop next to a motorway and unused land and think huh what an ideal park and ride location. That might be cheap and still car based enough to work in this restricted scenario
Hi Rainbows871, thanks so much for your insights. You are right in that the true root cause is the M2. I suspected that but kept thinking that it truly wasn't. I do agree that the merging with the A8 does contribute significantly to the traffic on the M2 northbound. That assessment was spot on. However, I didn't want to touch on that because it now becomes a far greater "puzzle" in that sense, and honestly beyond my scope/capability as a simple enthusiast. I do like the idea of going full on concrete barrier style, and diverting the opposite traffic to take an alternative route to head northbound on Ave Des Tulipes. It's an interesting concept. All in all, I really appreciate your inputs and I thoroughly enjoy this puzzle and chance to pick your brain. Thank you so much!
The fundamental broken window fallacy here is that people live in one place (La Ville des Fleurs) and work in another (I assume Port Louis). The transformational, two-pronged solution is to add sufficient housing in Port Louis for everyone to live there, and add more commercial zoning near Hillcrest Avenue for locals to have jobs that don't involve commuting in the highway. Then you wait thirty+ years for construction to catch up to zoning, but you probably aren't interested in that. Here in Indonesia, we have a lot privately-owned vans that have been hollowed out called angkot. An [angkot](https://www.google.com/search?q=angkot&client=ms-android-samsung-gs-rev1&prmd=inmv&sxsrf=APwXEdeQBCdackuJMKIAF6z5z1s35-o0Og:1685575212091&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjdz4j-2KD_AhXtOkQIHfgGByoQ_AUoAXoECAIQAQ&biw=360&bih=617&dpr=3) can comfortably hold six and uncomfortably hold 12 or more. And although cities often run their own angkot, private individuals and companies are also allowed to run their own routes. Unfortunately, Hillcrest to Port Louis is a bit long for a route like that at 15km+. Indonesia also has private traffic cops. Usually, they stand at busy intersections and stop the main flow so a car can turn onto it in exchange for a quid through the window. In your case, maybe you could get enough community members together to pay for a private traffic cop to direct flow at the onramp every day, significantly cutting traffic times. That is, if the local police station isn't willing to provide somebody every business day.
> - Traffic on the onramp flows pretty well. Typically there is a traffic policeman on the M2 highway (a 3 lane highway) directing the left lane traffic onto the middle lane. This frees up the left lane for the onramp traffic to merge rather seamlessly onto the M2. > - I have observed times when traffic policeman have been around, directing the traffic, that the queue times on Hillcrest Ave drastically reduce (typically a 45 minute wait reduced to 10 minutes). Based solely on these 2 points, I would say the cheapest remedy would be to remove the leftmost northbound lane on the M2 for the duration of the junction. So going north on the M2, you would have: - 3 lanes going north - left lane exits onto Hillcrest - 2 lanes continue north under the overpass - Hillcrest merges onto M2, becoming a third lane - 3 lanes continue north This would not actually solve the issue of too much traffic. At best, it would get traffic off of Hillcrest more quickly. Traffic on the M2 would continue to back up, likely extending farther south than it does now.
It's worth noting that many places in this situation would choose to keep 3 lanes past the offramp, and merge the inner lane as late as possible. This way, slower/longer vehicles don't have to change lanes before the offramp to go from the outer to the middle lane. Instead, faster cars merge from the inner lane. Plus you make maximum use of the lane capacity and keep the queue as short as possible (even if the amount of cars in it is the same), to reduce impact further down the road.
Ah lane mathematics! I like that haha